NinjaBunny9000 has created a life-sized replica of BMO from Adventure Time. The case is 3D printed and the buttons on the front are routed via the innards of a generic SNES controller. The battery can last for around 24 hours and he has added a wireless games controller as well for the full range of controls. The software side is RetroPie and is displayed on an 8-inch screen. You can see more photos of the build on his Imgur page.