Rotom's basic body looks similar to Castform, but Rotom has no real relation to any other species, since it doesn't have any evolutions or pre-evolutions. Rotom has a body of plasma. It also has teeth, which are often seen. Rotom also have unique eyes that have a dividing line across them. Rotom themselves are shaped like lightning rods, while the blue aura of electricity around them takes the appearance of lightning.