Carmen is a serpentine sea monster from the episode Serpent of Evil River. In the episode, the Captain forces Eustace, Muriel, and Courage into trying to catch Carmen, until Muriel realizes that Carmen, unlike her outward appearance and reputation would suggest, is really not a vicious creature, but is in fact very friendly and only wants an audience to listen to her beautiful singing voice. With this new knowledge, Courage protects Carmen from the Captain and in return she tows the boat carrying Courage and Muriel back home. However, Eustace had been abducted by monkeys during the fight.
- At the end of Mondo Magic, Carmen is seen on the TV chasing Eustace just before Courage pulls Eustace out of the TV as a magic trick.
- Her name is a reference to the opera "Carmen".