Treevil is an enemy found in Super Mario: Multicolored Mayhem, primaraly in haunted levels like Rickety Steppe. They disquise as normal dead trees, But if Mario gets too close to it, It chases him and attempts to eat him. If it does eat Mario, the player must repetitivly press A to get Mario out. 

Full Name Treevil
Gender Unknown
Species Tree/Treevil
First Appearance Mario and Luigi: Bowser's Inside Story
Latest Appearance Super Mario: Multicolored Mayhem