He was voiced by Frank Welker.
Role in the film
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, awakening Reggie, who charges at him. The chase ends with the Dogcatcher's van colliding with Reggie, 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 the young pup. Reggie, wanting to get revenge on Scamp for getting him sent to the pound, furiously charges at Scamp, but the chain attached to his collar kept him from attacking Scamp. The chain eventually broke and he grabs Scamp. Tramp then bursts into the pound just in time to save Scamp and battles Reggie. Tramp fights fiercely against Reggie, but he throws Tramp into a wall, knocking him out. Before Reggie is about to kill Tramp, Scamp bites Reggie's tail, causing Reggie to howl in pain. Reggie 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 Reggie could run outside. Reggie then runs into the iron bars of his cell door and gets knocked out.