He has the appearance of a giant, mutant, one-eyed monster, with a long enormous tail. He is lime green in color with a light green stomach and light purple lips.
When SpongeBob and Patrick fall into the abyss, The Sea Monster is in the bottom. The Sea Monster has been asleep for 79 years, so he bought a lot of Krabby Patties and Chum Patties, because his last meal was 79 years ago. He has a cruel attitude, seemingly evil, strong, and very respectful.