Cap'n Crunch is a mascot for the Cap'n Crunch's cereals.
He has appeared in episode "G.I. (Annoyed Grunt)", where he was in the mind of Homer saying "Stay crunchy in milk!". He also appeared in the episode "Dangerous Curves", where he was brutally killed by Bart while he was playing a game called Cereal Killer.
When Kirk and Luann Van Houten got lost at sea, Milhouse stayed with the Simpsons family. Next morning, Homer wanted to cheer Milhouse up. Homer offered him Cap'n Crunch cereal but then learned there is a picture of a captain on the box and tried to find another thing not to remind Milhouse's parents' doom to Milhouse.