Grumpig is a Pokémon based upon a pig that is bipedal. The lower half of its body is black, while the upper half is purple. There is also black on its ears and arms, while its hands and feet are purple. There appear to be three shining black pearls on its body, two on its head and another on its mid-section where the black half meets the purple. These pearls are related to Grumpig's strong psychic powers. Its large ears are useful for hearing and properly directing the sound to the inner ear. It also has a pink snout on its face, along with human-like oval-shaped eyes and a mouth. One of its most notable features is its long and curly pink tail, that may have been what was used to bounce in its previous form, Spoink. It is unknown whether Grumpig is able to use the spring-like tail to its advantage aside from using the move Bounce.