|Location:||Himself, Land of Ooo|
|First Appearance:||Memories of Boom Boom Mountain|
|Portrayer:||Matt L. Jones|
Mountain Man is a living mountain who appears in "Memories of Boom Boom Mountain." He hates when the Marauders roughhouse, and cries because he is tired of the violence involved in the Marauders' roughhousing and can't look away. He seems very fragile and caring of both people's and animal's health and well-being. He cries boulders out of his eyes, often causing avalanches. He was the first character on Adventure Time to say "math" as a profane word.
He is located next to a Mountain Man who enjoys staring at his beautiful back, which poses a problem. Mountain Man wants to look away so that he won't see the Marauders roughhouse, but the female mountain enjoys staring at the male mountain's back.
Mountain Man is large, jagged, and tall. He features grassy areas about himself. The grass and trees are mostly on his knees, feet, and arms, which he has despite being a mountain. His appendages haven't been used in the show, and they haven't really been emphasized as of yet. He also has holes for eyes and a mouth, with a nose between them. There is also another mountain who stands behind him that loves staring at his gorgeous back, which has short grass, a stream and two hills which appear to be his butt. He has the voice of an old man.
Mountain Man is very temperamental. He's been upset due to the Marauders. He obviously cares for other creatures, since he got mad at Finn when he tied animals to the Marauders. He also cares about their safety and health.