His first appearance is when Buster sends Scamp to get the tin can from Reggie's Alley, in order to prove himself worthy of becoming a Junkyard Dog. Reggie is asleep with the can under his paw. Scamp manages to steal it, but he walks into a trash can on his way out, accidentally awakening Reggie, who charges at him. He then breaks out of the alley, chases the other junkyard dogs, then goes after Scamp and Angel, but the dogcatcher's van blows smoke on him, causing him to go blind and with his eyes shut, goes the wrong way. He confronts Scamp and Angel again, during which Scamp bravely growls at him. The chase ends with the dogcatcher's van colliding with Reggie and him crashing into a food stall, after which the dogcatcher takes him to the pound.
Reggie appears again later when Scamp is thrown into the pound and is put in the same cell as Reggie. Scamp then sees a sleeping Reggie who awakens and spots him. Reggie, seeking revenge on Scamp for getting him sent to the pound, furiously charges at him, but the chain attached to his collar keeps him from attacking Scamp. It eventually broke and he grabs Scamp. Tramp then bursts into the pound just in time to save him and battles Reggie. Tramp fights fiercely against him, but he throws Tramp into a wall, knocking him out. Reggie nearly kills Tramp but Scamp then bites his tail, causing him to howl in pain. However, he then shakes Scamp off, throwing him into a wall and knocking him out this time. Tramp awakens and uses his speed to outrun Reggie, and then locks his cell door before he could run outside. Reggie bumps his head on the iron bars of his cell door, and he falls to the floor, unconscious.