The New Scooby-Doo Mysteries - Season 1 - Eps 20: The 'Dooby Dooby Doo' Ado
The gang heads to Las Vegas's, Circus A Go-Go, to see cousin Dooby Dooby Doo in concert. It then seems that someone is out to steal kidnap Dooby and steal his fancy collar.
About The New Scooby-Doo Mysteries

Title: The New Scooby-Doo Mysteries
First Air Date: 1984-09-08
Last Air Date: 1984-12-01
Status: Ended
Rating: 8.5/10 (from 100 votes)
Language: EN
Seasons: 1
Total Episodes: 26
Network: ABC
Genres: Animation, Family, Comedy, Kids, Mystery
Production Companies: Hanna-Barbera Productions
Synopsis
Picking up where 'The New Scooby and Scappy Doo Show' left off. The main difference being that the team is now occasionally joined by Daphne Blake and friends to solve mysteries together.
Cast

Casey Kasem
Shaggy Rogers (voice)

Heather North
Daphne Blake (voice)

Don Messick
Scooby-Doo / Scrappy-Doo (voice)

Frank Welker
Fred Jones (voice)

Marla Frumkin
Velma Dinkley (voice)