Professor Cozmo
In the games, Cozmo gets caught up with either Team Aqua or Team Magma (Team Magma in Emerald) when they invite him to help excavate meteors at Meteor Falls. Of course, they're actually after the meteorite for themselves—they steal it to power their machine up on Mt. Chimney. After you take them down and grab the meteorite back, Cozmo rewards you with TM27 (Return).
The anime version plays out similarly. Cozmo runs into Ash on Mt. Chimney in the episode "Fight for the Meteorite," though the broad strokes stay the same. He's voiced by Tomohiro Nishimura in the Japanese version.
In the Pokémon Adventures manga, Cozmo initially believed Team Aqua were actually the good guys, so he willingly helped them out with the meteor and their contraption on Mt. Chimney. The Chuang Yi translation mistakenly called him "Professor Starstone," but that got corrected in later appearances. He's apparently close with Roxanne and was actually her teacher at some point.
Content compiled by AnimeList.moe from publicly available sources.
