Wurmple is a small, caterpillar-like Pokémon. Its body is mainly red with a cream underside and face. It has large yellow eyes with dark pupils. It has one sharp yellow stinger on its head and two of them on its rear. It has a tall, erect, red spine behind its forehead and a similar, smaller spine behind that. It has small spikes running down the top portions of its body and five pairs of stubby white limbs.
