Crash (Regular Show)
Recent arrival to the Rock & Roll Underworld in the "Guitar of Rock" episode (17 March 2014) of Regular Show.
After Benson breaks a Flying V guitar signed by Bruce Rock, he, Mordecai, and Rigby (disguised as Max Amps, Zander Mercury, and King Pluto) have to go to the Rock & Roll Underworld for a new autograph.
The bouncer's list has him as "Thrash"; we're guessing the bouncer isn't very detail-oriented.
His name is likely inspired by real guitarist Slash of Guns 'n' Roses.