Poliwag resembles a blue, spherical tadpole. It has large eyes, a pink mouth, and a long, mostly transparent tail. It has newly developed legs that still are not used to walking. Poliwag's most famous feature is the black and white swirl on its abdomen, which is actually its innards showing through its semitransparent skin. The swirl looks clearer after it eats, and the skin is very elastic so that it will not break if the Pokémon is bitten. The direction of the belly spiral differs by area, with the equator being thought to have an effect on this.