The Composite Object found in the Garry's Mod maps gm_excess_construct and gm_excess_waters. It's a really cool shape, makes for an interesting desk toy or sensory / stim toy. I nicknamed him Earl, he was a very good boye.

I modeled this one by hand based off of the measurements - they're guaranteed to be 1:1 to the original object in the game.

Example shown is printed in Bambu PLA-CF Black, which makes for very nice and clean angular lines, but it'll print great in any PLA. Beige PLA or a stone-like filament would be the most accurate to the original.

Supports are required - I recommend printing it upright even though that requires more support material as it keeps the surface finish consistent across the visible faces. You can auto-rotate it to stand on its back which minimizes the supports required down to only one face, but this leaves the back with a different texture from the rest of the object.

If using as a stim toy, printing 6 walls, 100% infill is best because it gives it a satisfying weight (~33% more than a typical strength preset).