A Pup Named Scooby-Doo - Season 2 - Eps 2: The Return of Commander Cool
The doctor tells everybody to just play along with Shaggy's amnesia. So now Shaggy thinks he's Commander Cool. When he finally gets his memory back he doesn't remember what just happened.
About A Pup Named Scooby-Doo

Title: A Pup Named Scooby-Doo
First Air Date: 1988-09-10
Last Air Date: 1991-08-17
Status: Ended
Rating: 7.6/10 (from 275 votes)
Language: EN
Seasons: 4
Total Episodes: 30
Network: ABC
Genres: Animation, Mystery, Comedy, Family, Kids
Production Companies: Hanna-Barbera Productions
Synopsis
The world's favorite chicken-hearted canine, as a puppy? That's right! And the old gang is back with him. Shaggy, Daphne, Velma, and Freddy are all here as gangly kids — goofing off, solving kid-size mysteries, and having run-ins with ghouls, ghosts, and goblins.
Cast

Don Messick
Scooby-Doo (voice)

Casey Kasem
Shaggy Rogers (voice)

Carl Steven
Fred Jones (voice)

Kellie Martin
Daphne Blake (voice)

Christina Lange
Velma Dinkley (voice)

Scott Menville
Red Herring (voice)