Raichu is a rather small tailed bipedal rodent. It is able to run faster on all fours. Like Pikachu, from which it evolves, Raichu has long ears and feet, and stubby arms. Also like Pikachu, Raichu has two horizontal brown stripes on its back. Its long, thin tail has a broad, lightning bolt-shaped end. Unlike Pikachu, however, it does not have fingers.

Raichu is yellow-brownish in color, with a white belly. Its arms are halfway brown, as well as its feet. The soles of its big feet are tan colored. Its bifurcated ears are brown on the outsides and yellow on the insides, and end in a distinctive curl at their bottom-most point. The electric sacs on its cheeks are yellow.