|Introduced in||"Dad's Dungeon"|
Ugly Monster makes his only appearance in "Dad's Dungeon." Finn and Jake encounter him when they are choosing between taking either his path or the Flower Path. His path isn't chosen because he's "super gross," as stated by Jake. Ugly Monster gets sad that his path isn't chosen, despite the fact that he originally intended to be an obstacle to the duo. As a path blocker his size and appearance are his main attributes; his gross body covers most of the path's room.
Ugly Monster is a misshapen green blob with many lumps covered with stubbly hair, a large orange-lipped mouth running vertically down his face that resembles Hunson Abadeer's mouth when he is in his monster form. A small flower is ironically placed on top of his head. He sits in a puddle of his own slime that spouts out of his body.
None shall pass!
Wait! Why don't you want to take my path?