From Bulbapedia, the community-driven Pokémon encyclopedia.
Mirakle B. is the rightful successor to Miror B., or so he claims. This may mean he is Miror B.'s son, or he could perhaps just be an obsessive fan of Miror B.'s.
He is only beginning to work on an afro. He has colored his helmet to look like a Poké Ball, in imitation of Miror B.'s afro. His theme music is a sped-up, off-key version of Miror B.'s theme.
He appears in Pokémon Colosseum at Miror B.'s Hideout in the place of Miror B. after Miror B. himself has been defeated. He vanishes after the player has defeated Evice.