I don't know of an episode where all the gang becomes dogs, but there is an episode where Shaggy and Scooby swap minds ("Who's Scooby-Doo?", part of "The Scooby & Scrappy Doo Puppy Hour."
I believe you are referring to the episode titled "The Sludge Monster From The Earth's Core" of "A Pup Named Scooby-Doo".
The leader of the gang in Scooby Doo is Scooby Doo.
The best Scooby-Doo episode is the Harum Scarum Sanitarium
Scooby-Doo and the gang were in the episode titled "Bat-Mite Presents: Batman's Strangest Cases!". This isn't the first time Batman and Scooby-Doo have been seen together though. Batman and Robin guest starred on "The New Scooby-Doo Movies" in the episodes "The Dynamic Scooby-Doo Affair" and "The Caped Crusader Caper" in 1972.
The first episode of the Scooby-Doo franchise is "What a Night for a Knight" of "Scooby-Doo Where Are You!". It first aried September 13, 1969.
The episode is "Jeepers, It's the Jaguaro!" of "The Scooby-Doo Show".
the scariest episode (my opinion) of scooby isIt's Mean, It's Green, It's the Mystery Machine
The "What's New, Scooby-Doo?" episode "It's All Greek to Scooby-Doo" has a villain who used a centaur disguise. There's a real centaur in "Scooby's Escape from Atlantis" (in "The Richie Rich/Scooby Doo Show", an episode with just Shaggy, Scooby and Scrappy).
in the movie scooby doo 1
Scooby doo ( the dog), Shaggie( scoobies owner), Velma, Fred, and Daphne
it is titled Toy Scary Boo, and it is an episode of What's New Scooby Doo.
"Bedlam in the Big Top" is the Scooby-Doo episode with the hypnotic Ghost Clown.