Thundurus is a blue, muscular, vaguely ogre or genie-like Pokémon. He has a zigzagging, jutting white mane on the back of his head, one purple horn, blue ears, yellow eyes, and a white, pointed mustache. His muscular arms are spotted with purple, and his navel also has a spot of purple. He has a trailing cloud for a lower body, and his long, curling, indigo cord-like tail is adorned with various spiked, spherical structures.