The Sea Rex is a sea creature that was planned for Munch's Oddysee but was cut from the final version. The Sea Rexes are believed to be a kind of an omnivore. According to information found on the Oddworld website, Sea Rexes are large, seabound organisms. They have a large eyeless head, a mouth full of sharp teeth, limbless body about the size of their head, and a long, flat sort of tail.  
There have been rumors of a "Deleted Scene" of Oddworld: Munch's Oddysee, where a school of Gabbits swims when being preyed on by a Sea Rex.
Click Here to be redirected to a YouTube video of the deleted scene!
- According to existing information regarding the appearance of the Sea Rex, it can be assumed that the creature resembles a serpent-like version of the Tyrannosaurus.
- Judging to the deleted videos info, it seems sea rexes don't prey on gabbits. But this could be because that sea rex wasn't hungry.
- One possible reason why the Sea Rex wasn't added to the game is because they are humongous. So, in order to avoid getting eaten by one, they had to make the water levels bigger. But, it could also be that Sea Rexes are extinct during the events of Munch's Oddysee.