Ghost Man

Ghost Man makes his appearance in "Blood Under the Skin." Finn and Jake encounter him in the cave where the Armor of Zeldron is located. He is highly addicted to the game Drop Ball and won't let anyone pass unless they beat his high score, which is 6. Finn and Jake sneak past him while he is instructing them on playing Drop Ball, but when they get the armor, he becomes angry and turns into a monster because they weren't listening to him. He then mistakes Jake for his mother while Jake is wearing the Armor of Zelderon. Jake tells him to go outside, and he listens thinking Jake is his mom. This causes him to revert to his normal self and cures him of his addiction to Drop Ball. It is unclear how exactly sun works with Ghosts in Ooo, but it seems likely that Ghost Man is not undead.

Appearance
Ghost man is a semi-transparent pale green color. His torso is shaped like a bean, and his butt is the most noticeable feature on his body. He is vaguely humanoid though significantly simpler in shape. He has thicker lips than most characters.

In his revived state, he looks exactly the same but is a more saturated green color and is no longer transparent.

Quotes
"Dropball is an extremely addictive, high intensity game designed for people everywhere. Now, I don't want you to be intimidated, but my high score is six."

"You did not watch my Dropball technique! I give you first-hand tips that no one else knows and this is how you thank me?! I absolutely disagree with that!"

"Oh, thank you Finn and Jake! You've freed me from the addiction of Dropball!"

Trivia

 * Ghost Man's addiction to Drop Ball is inspired by Marc Griffin and his enthusiasm for "Bulletball," the sport he invented.
 * Ghost Man can be defeated with three hits in Sound Castle 2.
 * He is also in Legends of Ooo, where one must find his ball so he can scare away an ogre.
 * He also makes a cameo appearance in "Paper Pete."
 * He is the only known ghostly figure to walk instead of floating.