Koala (Scooby Roo)

Koalas are small marsupials from Australia.

Physical Appearance
They have brown fur, instead of gray in the show.

Perosonality
It once whacked Scooby-Doo with a stick.

Scooby-Doo! And the Legend of the Vampire
Scooby got his hands stuck in tree sap on a tree and a koala bear whacks Scooby with a stick thinking he's an intruder. When Scooby finally got realased, the koala laughs.

Trivia

 * Koalas were known as koala bears.