Mischieasel is a Dark-type baby Pokémon. It evolves into Sneasel when leveled up holding an Icy Rock during the night, which evolves into Weavile when leveled up holding a Razor Claw during the night as well.
Mischieasel is a bipedal baby Pokémon that resembles both cats and weasels. It is primarily grayish black with four bright pink feathers for its tail and a single one on its left ear. On its forehead and chest are yellow, oval markings. The forehead oval marking is large on the female than on the male. It has red eyes with black eyelash-like markings on the edges. Its feet and hands have two short, retractable claws each.
Topaz Pokédex entry
It likes to hone its claws by repeatedly scratching a tree. It can camouflage in the dark.
Jade Pokédex entry
It is extremely mischievous and likes to prank unsuspect targets by sneak up, scratch their back and hide in the dark.
Mischieasel appears to be based on the kamaitachi, weasel demons with sickles on their front legs. It also shares similar traits with cats and weasels, from unusually cruel behaviors to even superstition, from cat demons or black cats of Western witchcraft, to Japanese superstition of weasels, being known in their respective cultures for being sneaky and associated with "evil" and misfortune. Its eye markings are similar to that of ones in Egyptian style, possibly Horus's.
Mischieasel is a combination of mischievous or mischief and weasel.