Tobias R. Kellgren played drums in Dissection between 1995 and 1997, after Ole Öhman had left the band. Kellgren was replaced by Bård Eithun.
Tobbe Kellgren joined In Flames in October 2005 as a session drummer for their tour with Motörhead, while regular In Flames sticksman Daniel Svensson awaited the birth of his second child.
Tobias Kellgren also joined Wolf for the recording of their fourth album "The Black Flame", replacing previous sticksman Daniel Bergkvist.