The Evil Sea Monster is a large sea beast that guards the Helm of Ultimate Wisdom in Scholarville. It dwells in the sewers of the lone castle far from the village, and its existence was kept secret until Kaos gloated to the Skylanders about the monster.
- Kaos intially refers to the monster as just a legend. However, while he is searching for the Helm of Ultimate Wisdom with the Skylanders fighting the monster, Kaos can be heard saying he hopes the monster has already eaten the Skylanders.
- The Evil Sea Monster is the fifth sea monster in the series, the previous ones being the Leviathan, the Rainfish, the Titans, and the Hydra Hatchling.
- Despite not being a Doomlander, he is still technically "weak" against Imaginators, due to being the true boss of the stage.