From Bulbapedia, the community-driven Pokémon encyclopedia.

A St.Performer (Japanese: 大道芸人 Street Performer) is a type of Pokémon trainer that first debuted in the Generation III games, appearing in Pokémon Colosseum. They are young women dressed up like magicians in tutus, top hats, and carrying wands. Like many of Orre's trainer classes, they don't specialize in any particular strategy or Pokémon.