ニャース, Meowth, Nyaasu, Miaouss
Nyarth is a member of Rocketdan Team Rocket more specifically part of a trio with Musashi and Kojirou that follows Satoshi and his friends around in the Pokmon anime usually trying to steal Satoshis Pikachu. His major difference from other Nyarth and nearly all other Pokmon is that he can talk and walk on two legs like a human. Source: Bulbapedia