Quite a few years old, but I still really like the concept. Someone challenged me to design rotom...but rat. It's a long story.

Alt text: A drawing of a rat fakemon with six forms named radapt. The base form (bottom right) is a normal/poison type white rat with multicolored eyes. The lightbulb form (top right) is a purple electric/poison type with a broken lightbulb on its head and a bolt of electricity between its ears. The bottle form (middle) is a blue-grey water/poison type with its lower body stuck in a water bottle, turning to liquid. The match form (bottom left) is a magenta fire/poison type with flame-shaped fur and a used match in its tail. The skull form (middle left) is a green, levitating fire/ghost type anchored by a skull in its tail. The banana form (top left) is a light yellow grass/poison type with an old banana peel on its head.