With a mark like that, I couldn't resist giving him an appropiate nickname as well [SwoSh]

In case you don't know: Any Pokémon you catch in the wild (not hatched from an egg, given to you via in-game trades or caught in dens) has a certain chance to come with a "mark" attached. These work like Ribbons, you can toggle them on/off and they stay attached to the Pokémon in question even if you trade or evolve it.