Belly of The Beast is the 18th level of Doom: The Dark Ages contains two collectibles and they can both be found on the floor of the level. Collectibles consist of toys, codex entries, and weapon skins you can find hidden in most levels.

Check out our Doom: The Dark Ages Collectibles Guides Hub for links to guides for every level.

Collectible 1 – Codex Entry

In the third section from the start of the level (where you punch a third objective), right after clearing all of the enemies, this is located near the third objective. It’s out in the open, although it is in a pool of poison, so watch out.

Collectible 2 – Komodo Toy

Also in this area, there is a hallway blocked by a shield switch. Use the switch, enter the hallway, and jump down the hole. This will start a battle that lasts for several waves, but keep fighting until the encounter ends, at which point you can pick up the collectible.