|What's missing, Scoobypedia?|
He was a hairy man.
He acted dog-like, except when was he struck by the light of a full moon, which caused him to morph into a fearsome wolf-monster.
Shaggy & Scooby-Doo Get A Clue!
He was one of the monsters that got out of the movie when the techies were testing it. Phibes thought he was just annoying until Rusty's wolf transformation made him run for his life. (Super Scary Movie Night)