From Bulbapedia, the community-driven Pokémon encyclopedia.
Butler (Japanese: バトラー Batora Butler) is a former Team Magma scientist and magician. He was fired from working with Team Magma because an experiment to create a Groudon from a fossilized remnant of it had failed. Butler realized that he needed a stronger energy source for the regeneration process. The power that he sought was only available once in a millenium. Butler and his girlfriend, Dianne found the chrystalized "cocoon" of Jirachi in Forina.
When Ash, Brock, May and Max found Butler at the Millenium Festival, Butler presented Jirachi to Max because Max was supposedly the friend that Jirachi needed to find so it can awaken when the Millenium Comet appeared.
When Jirachi awoken from its thousand-year sleep, Butler set up his machine and gave it a test-run a night later. Dianne informed Ash and the gang what Butler was up to and decided to take Jirachi back home.
When Jirachi was sent home and was about to go back to sleep for another thousand years, Butler showed up out of nowhere and snatched Jirachi. Butler then used Jirachi's power in the hopes to create a Groudon from scratch. However, he wound up with a manifistation of pure evil that resembled Groudon.
When the Fake Groudon started sucking up every Pokémon in sight, begged Ash and Max (everyone else was sucked up the Fake Groudon) to forgive him and help him to to set his machine in reverse to get rid of the big, red abomination. The plan was a success and Pseudo-Groudon was destroyed and everyone was released. After Jirachi finally went back to sleep, Butler and Dianne decided to stay and protect the Pokémon of Forina.
While Butler's only major role was in Jirachi: Wishmaker, he and Dianne made a cameo during the ending-credits of Lucario and the Mystery of Mew.
His Japanese voice actor is Kōichi Yamadera and his English voice actor is Wayne Grayson.
Butler makes a cameo appearence in Pokémon Diamond and Pearl on Route 229 as a Cool Trainer using a Level 55 Salamence and Dusclops. However this easter egg was not recognized by the translation team, which named him Felix. His girlfriend Dianne (Named Dana by the translation team) is next to him and the two can be engaged in a double battle or battled alone.
Butler owned the following Pokémon: