LEGO Set Review: 10404 Ocean's Bottom

10404 Ocean's Bottom, with 579 pieces, is the second largest in a series of five LEGO Classic sets themed Building Bigger Thinking, released in 2018 in celebration of the 60th anniversary of the LEGO Brick patent. If you're not familiar with them, the five sets, in order from smallest to largest, are:

The reason I chose this particular set out of the five is the octopus chef that's featured on the front of the box. The octopus is my favorite marine animal and the moment I saw it on the box art I knew I had to pick this set up for myself as part of my first ever LEGO Certified Store haul breaking out of my 13-year-long Dark Ages. The fact that this set is called Ocean's Bottom is just icing on the cake!

I've always loved the creative building LEGO themes such as Basic, FreeStyle, Creator (both the original theme and the modern-day Creator 3-in-1), Bricks & More, and today's Classic, so I'm not getting this just for the octopus chef or because I'm returning to LEGO in time for the 60th anniversary of the patent (but make no mistake these are still two major factors). I've had so much fun exploring all the new parts and colors I've missed out on and getting my creative juices flowing again.

Comprehensive reviews of LEGO Classic sets are few and far between as they're not popular among AFOLs, which is why I'm kicking things off with a review of 10404 Ocean's Bottom as the first ever LEGO set review on my site. Let's dive in and discover what lies at the bottom of the ______!

The box

These Building Bigger Thinking boxes are strikingly minimialistic, especially on the front which shows a brick pile, the models available to build with one standing in the foreground, the Building Bigger Thinking logo, set number and age range (plus piece count in the US) on the lower left corner, and a big red question mark on the right side with the LEGO logo as the dot, all on a plain background color. There is no other framing or embellishment to be seen like on other sets (and even other LEGO Classic sets!).

The top and left sides of the box display a creative prompt "what is at the bottom of the ______?" in several languages. I found it interesting that a blank is substituted for where I would have expected "ocean", but it looks like they really want you thinking about not just what lies at the bottom of the ocean, but elsewhere too. The promotional video here has some suggestions.

I was delighted to find out that the lime green in the bottom of the box exactly matches the paint on my walls!

What's inside

The box contains 7 main bags of parts sorted by color group, a bright green 6x12 plate, and building instructions. The color groups are:

Right off the bat, the proportion of red elements and green elements in this set is dismal, to say the least. Despite the sizes of the bags, there are actually more pink and purple elements than green ones!

Although there are a significant number of specialized parts, the proportion of basic bricks and plates is still pretty decent, with 144 bricks and 64 plates. 208 of 579, or just shy of 36%, is not too shabby.

Interestingly, all but one of these bags have a QR code printed on them. The red, yellow, green and blue bags have the same QR code, the white a different one, and the black yet another. Scanning these codes turns up some 7-digit numbers whose meaning is not immediately clear. Perhaps these are meant for internal use and to be ignored by the consumer.

Unfortunately, this set doesn't come with a brick separator — among the five Building Bigger Thinking sets, the only set that does is the largest one, 10405 Mission to Mars. LEGO Classic sets often come with a brick separator, even at smaller sizes (including the 221-piece 10692 Creative Bricks), so it was rather disappointing that this one didn't as taking apart a model for rebuilding after you've built it with more than half of the 579 pieces can be quite daunting whether you're 5 or 25!

New, noteworthy or rare parts

One thing that sets these Building Bigger Thinking sets apart is the inclusion of a 2x4 white tile with the "60 years" logo printed on with a nice shine to it. It's not shown here as I have a separate image of it a little further down.

Beyond that, 10404 Ocean's Bottom contains a handful of newly recolored parts introduced within the last year. Only one is currently unique to this set however — two dark pink 1x2x2 arched windows, one of which serves as the gaping mouth of the octopus chef. There are also four of these windows in light grey which are used in the towers of the undersea castle.

Clockwise from the top left corner of the first image:

  1. 4x tan 1x1 brick with studs on 2 adjacent sides (corner SNOT brick), appearing in great abundance as soon as it was introduced, especially in sets like 40174 Iconic Chess Set, 10255 Assembly Square, as well as this year's 21042 Statue of Liberty
  2. 4x yellow 1x1 round tile, sparsely scattered across a number of sets including 70620 NINJAGO City
  3. 2x dark blue 2x2 brick with curved top and 2 studs in the center, appearing in a handful of other sets including 10703 Creative Builder Box which I got in the same haul as this and will be reviewing soon
  4. 2x red horn, first appearing in a 2017 NINJAGO wave
  5. 2x white 1x3 panel tile
  6. 2x magenta 2x2 inverted slope, first appearing in two 2017 LEGO Friends sets as well as 70922 The Joker Manor
  7. 1x gunmetal grey 4x4 barrel, first appearing in 21309 NASA Apollo Saturn V
  8. 2x orange 2x4 double inverted slope, first appearing in 60167 Coast Guard Head Quarters
  9. 8x dark purple 1x1 plate with horizontal clip, first appearing in 41237 Batgirl Secret Bunker
  10. 2x dark pink 2x2 facet brick, new to this set and 41152 Sleeping Beauty's Fairytale Castle
  11. 2x dark pink 1x2x2 arched windows, new and unique to this set

Also not shown are the bright green and magenta flower-shaped 1x1 round plates which have a new five-petal mold in 2018. But you can read about them on Bricks Stack Exchange and New Elementary.

Honorable mention goes to the yellow 1x6x2 curved arch and the blue wizard hat, both of which were common in 90s FreeStyle and Castle sets respectively but stopped appearing except in the odd set or two in the two decades since!

Brickwork bricks/masonry bricks

Despite their irony (which I actually couldn't care less about), I'm a really big fan of LEGO brickwork bricks because their texture adds a lot of visual interest to otherwise plain walls. That's why every one of my reviews of sets containing them has a subsection dedicated to them.

10404 Ocean's Bottom includes 2x light grey 1x2 brickwork bricks, used in the undersea castle.

Building instructions

Being a 60th anniversary set, the included booklet starts off not with the instructions, but with a message about imagination, creativity, and how the LEGO brick has facilitated these in young minds over the years.

I was amused by how the very first page takes the mickey out of grown-ups by saying that your imagination is bigger than one. Not even bigger than a grown-up's imagination — bigger than a grown-up, period. This brand campaign seems to love its sass in general. But my favorite thing about the first page, of course, is the octopus, placed at an angle that just evokes playfulness.

Anyway, the booklet includes instructions for 4 models: a trumpet, an octopus chef, a rocket car, and a dragon. Instructions for a castle and a spaceship can be downloaded from The booklet also features a total of 6 inspirational models and 3 more creative prompts between sets of instructions.

For some reason, the dragon is rated as advanced building despite being the smallest model and using the fewest pieces, and minifigure building instructions are placed at the very end which is itself already very unusual, but what's even more bizarre is that only the female minifigure is shown. At least the placement can be explained by LEGO wanting to encourage kids to build the models first. The latter? I got nothin'.


This set includes two minifigures with plain but brightly colored torsos and legs, as well as the classic smiley face from the 80s and 90s (that have also been seen in Modular Buildings until 10255 Assembly Square, before the switch to modern faces in 10260 Downtown Diner).

As a testament to the quality and consistency of LEGO's manufacturing process over the generations, these minifigures' faces are completely indistinguishable from those of the minifigures that came in 4162 FreeStyle Multibox, a set that I bought in 1997 when I was 5 and remains one of my favorite sets to this day. This includes the size and position of the face print on the head, not just the use of the classic face at all (some 2000s sets have the faces printed a little differently).

That's right: these minifigures were made over 20 years apart.

A wide range of accessories includes the aforementioned blue wizard hat; a broom; two coffee mugs; a hammer and spanner; a motorbike helmet and visor; a scuba diving mask and flippers; a pearl silver nasal helmet, pearl gold longsword and pearl silver shield (not shown, used as a platter by the octopus chef); a chef's hat, frying pan and cleaver.

Food items include a pie, a carrot, a fish and a turkey drumstick. Most of these are being held by the octopus chef and are therefore not shown. (You seeing a theme here?)

The models

Before getting started on any of the instructions, the first thing I wanted to build was the "60 years" tile display from 40290 60 Years of the LEGO® Brick. Note that only the printed tile and four red 2x4 bricks are included in this set; everything else is from my existing collection.

The second thing I built was the little creature that represents the dot of the big red brick-built question mark in the promotional videos for these Building Bigger Thinking sets. Oddly, none of these sets gives you all the pieces you need to build it, but 10404 Ocean's Bottom happens to have two red 1x1 bricks with studs on opposite sides that substitute for a red 1x2 brick with studs on 1 side for mounting the eyes.

Now, on to the main models!


The first model they have you build is a trumpet. It's rated as easy building, and it is (for the suggested age range, not just for me), but what's really impressive about it is that the entire thing is built around sideways building techniques, from all four sides. There's even a 180° attachment at the very end of the bell with the flame yellowish orange 4x4 parasol!

This is actually my second favorite build out of all of them besides the octopus chef, for that reason plus that it looks absolutely charming. Kudos to the set designer for pulling off such an impressive yet actually (as in not deceptively) easy build!

Octopus chef

The second is the octopus chef. Words cannot describe the joy I experienced putting it together 🐙

It's pink, magenta, lavender and purple, it's got great personality, all eight of its arms can be moved up and down, and there is a bit of variety in the build so you don't just build the same thing eight times, but rather two sets of four.

The structure for the arms is identical to 40245 Octopus, July 2017's Monthly Mini Build (coincidentally, a year ago this review!), with a black plate with octagonal bar frame to which eight 1x1 plates with horizontal clips attach. Just the arms themselves are built differently, and even then curved elements are used in both models.

The octopus chef is seen holding a pie, a carrot, a turkey drumstick, a frying pan, and a cleaver. You can make it hold anything else, or even nothing at all, of course. This octopus can be anything you want it to be!

Because I love marine life so much, I've included a size comparison between the octopus chef and each of the main models of one of my favorite LEGO Designer Sets, 4506 Deep Sea Predators, which my parents surprised me with on my 13th birthday in 2005.

Rocket car

The third model is the rocket car. The rear thruster spins which looks pretty rad (the nose doesn't, but it doesn't need to), and the inside has space for a driver minifigure. The orange and white color scheme seems conventional for a rocket, but appropriate, and these are pretty bright colors after all.

This rocket car looks ready to burn rubber. Maybe even literally, if that trans-orange flame gets a little too close to the asphalt!


The last model the booklet contains instructions for is the dragon. It's small, cute (in a Fluffy the Terrible way, I guess), and it breathes fire. I especially like the dark purple wings — I think they pair excellently with the bright red body. The menacing eyes are a great cartoony scale to the body, and it's got a little tail that's hard to see behind the wings so I've provided a posterior view.

Even after building it, I still can't figure out why it's rated as advanced building.


Instructions for the undersea castle and the spaceship can be downloaded from

Unlike the dragon, the advanced building categorization is actually appropriate for the castle. It doesn't make use of advanced building techniques, but being the largest and most complex model it does take the longest and most pieces to build.

The castle has a portcullis that can be raised and lowered by grabbing the handle behind the battlements, and a working drawbridge that closes at least most of the way before the chain ends impact one another. Speaking of which, the chains can be difficult to attach for some, so parents may want to lend their kids a helping hand if they need it.

I like the marine vegetation that can be seen growing around the castle. These are mounted on the remaining two tan 1x1 corner SNOT bricks. I was unsure about the choice of lime green at first, but looking at the finished model now I think it works pretty well with the tan and light grey walls, and provides a nice contrast against the green base. Strange that it's all sat on a medium azure plate rather than a tan plate, though, since presumably the tan represents sediment and seabed.

The back of the castle has nothing as it's just a façade, but I'm not sure what those bricks with vertical clips are for. I wonder if LEGO wanted to include the bricks themselves in the set and just used these as substitutes for regular 1x1 bricks in this model.


This spaceship is designed in the style of Classic Space, a theme I never had a chance to get into as I was born much later. We did use to have some Blacktron 2, Ice Planet, M-Tron and UFO sets, though. I particularly enjoyed 6975 Alien Avenger.

Anyway, this spaceship is equipped with two flick-fire missiles. Apparently people hate those things. I don't mind them — in fact, I enjoyed playing with them — as long as they're not pointed at someone. Unlike stud shooters, they're practically impossible to trigger by accident, and the projectiles are much less likely to get lost after being fired as they're much bigger and don't roll all over the place.

Like the rocket car, there is space for a minifigure to pilot the spaceship. Unlike the rocket car, though, the spaceship is, intentionally, comically undersized. This is what is meant by "minifig-compatible but not minifig-scale". It's not necessarily a bad thing, but it helps to know the difference.

My custom models

After finishing the six main builds, I wanted to see what I could do with the remaining pieces. There are at least a couple hundred remaining so I actually had quite a lot at my disposal — enough to make not one, but two average-sized custom models without taking any of the others apart. With more time, I easily could have made four or five; the most notable parts I left unused were vehicle parts: two pairs of wheels (one pair of each size gets used by the rocket car as shown above), and two windscreens.

This being a set called Ocean's Bottom, though, vehicles were not what I had in mind at the time.


The first model I built was a nudibranch, a type of sea slug. Nudibranchs are known for their bright colors, so this gave me a bit of an excuse to have some variety in the color scheme as the sheer number of colors in LEGO Classic sets means you don't get very many of one color at all.

I know I said vehicles weren't what I had in mind, but seeing just how many vehicle parts were left unused I felt like I owed it to the set designer to use at least some of them. So, I fitted this nudibranch with an engine so it can go faster. It looks pretty happy about it!

I especially like how I built its rhinophores using the two yellow curved bricks on light grey 1x1 nose cones that are then embedded into the bars of the light grey 1x2 modified plate.

Although real nudibranchs have pinholes for eyes rather than fully developed eyes, the eyes I put on mine are indeed at anatomically correct locations, and this being LEGO Classic, I'd still choose these expressive eyes over, say, a pair of black 1x1 round tiles, or BrickHeadz eyes (I reserve those for BrickHeadz characters only).

Serendipitously, there is also space for a minifigure to ride this nudibranch (i.e. I did not design it that way). That's one of my favorite things about LEGO, and making things in general: accidental features.

Sand dollar

The other model I built was a sand dollar. I had originally wanted to build a sea star, but I wasn't sure I could pull it off, so I thought of a spiny sea urchin instead, but I didn't know how to make it look spiny, so I ultimately went with making a sand dollar. While technically also sea urchins, sand dollars are round and flat and don't have many outward-facing (or upward-facing) features.

And that's exactly what my sand dollar is. Just an attempt at making something round and flat using just basic rectangular bricks and plates that surprisingly worked. I even got a bit of sideways building in with the two medium lavender 1x1 bricks with a stud on 1 side. However, unlike the octopus chef which also uses these bricks, the eyes are mounted on the top studs here, and the side studs are used to build some more of the surface of the body. (Sand dollars don't have eyes.)

You can see that the two light pink 1x3 bricks are perpendicular to each other in more ways than one. I also wanted to make use of that 3x3 cross plate whether I was making a sea star, a spiny sea urchin or a sand dollar and I'm glad I managed to — you can see this on the underside of my sand dollar. You could even look at that element as a crude suggestion of the sand dollar's test (its skeleton)!

The images show the sand dollar standing upright for ease of photography, but it's really meant to lie flat, since that's how sand dollars are.

And yes, live sand dollars are often purple, just like many other sea urchins. They're actually really pretty, and mesmerizing to watch.


As mentioned in the introduction, I had so much fun building and exploring all the cool new elements and techniques I'd missed out on. I'm really happy to be back building with LEGO bricks and I'm so glad I picked this set to start out with. My love for marine life made picking this set among the other Building Bigger Thinking sets a no-brainer, and for the price I got a really good number and selection of elements to play with.

Although LEGO Classic sets are rather lacking in the quantity department due to the by-now-massive color palette, even if you're not into this set for what it is it's still a great parts pack, especially if you can find it at a deal. I personally am still deciding whether I want to part this set out as I want to use many of the bricks for other creations, or if I want to keep it as one set (which is what I always did with my LEGO Designer Sets).