BMO (phonetically spelled Beemo) is Finn and Jake's living video game console, portable electrical outlet, music player, roommate, camera, alarm clock, flashlight, strobe light, skateboarder, friend, soccer player, and video player. It makes its appearance in the title scene of the Theme Song of every episode of Adventure Time, just before Finn and Jake pound their fists together. BMO is the only one who can press the button under its D-pad to send a target to its main-brain-game-frame. BMO is characterized as a loyal, trusting, and helpful friend who is protective of Finn.
BMO looks like a half-Macintosh half-Game Boy Color with Atari 2600 controllers. It also shares some traits with a Vectrex.
BMO is a medium-size green handheld gaming device, sometimes appearing with one or two controllers attached to it. When it's not being played it has an 8-bit face. The letters "BMO" are printed on its sides, indicating its name. Arms emerge from the "O."