The Trench Monsters are a group of large, ravenous monsters that live in a trench of the outskirts of Bikini Bottom, and Shell City, similar to the town of Rock Bottom. They are only featured in The SpongeBob SquarePants Movie, where SpongeBob and Patrick had to cross this area full of monsters, and the creatures, and beasts were not a threat, since they believe they are "Invincible" and nothing can hurt them, seeing how Mindy gave them "Mermaid Magic" turning them into men. These monsters really wanted to eat them, until they went along with the song and became their friends, only to be turned down after the "Men" called them hideous, and disgusting. They appear in a cameo in "A Life in a Day," where Patrick attempted to jump them on a skateboard, tied to his back.
An Angler fish
A Translucent fish
A Giant Humbolt Squid
A Humongous Black Eel
A Gigantic Snail, with eyes for his shell
A 3 eyed Red Monster
A Black monster, with flexiable eye stalks
A Green monster, with hands for eyes
A Giant Lobster (Game only)
A Giant blue Crab
An 8 eyed Squid (Game only)
See through fish monster
Big yellow monster, with an eyestalk
3 slow monsters
Giant red eel
A giant green hand
A Giant Green Crab
A Ball monster
A Three eyed Green Fish Monster
A Giant Clam, with one eye and teeth
A big orange fish monster
A purple lobster/dragon monster
A one eyed Green Monster, with arms on its head
A Giant Red Squid
Most of them are based on of real deep-sea creatures, such as the Angler, and Humbolt Squid.
The Monster making the yelping sounds at the stairs are, is not actually seen.
The light on the road-like monster is designed to look like a traffic light.