'r'r 4 is a glitch Pokemon found in Pokémon Yellow. It is a Water-type Pokémon. It can only be acquired via the Johto Guard Glitch with Politoed. It occupies hexadecimal slot E1 and will become a 'v if traded to Pokémon Red and Blue. Although the summary says it's pure Fighting-type, type effectiveness suggests pure Water-type.
It also features a glitch screen, particularly the purple-tint variant. It can evolve into a ' B' ゥ or a Growlithe at level 4. It uses sprites of random Pokémon (depending on level, e.g.: Mew's at level 6 or Electabuzz's at level 9).