The mouse lives in the area of Rocky Point Beach.
It looks like a typical gray-furred mouse with a pink nose.
He was brave because he can fight a big dog like Scooby-Doo, which he was easily annoyed at when he lost.
Scooby-Doo, Where Are You!
Scooby-Doo, Shaggy Rogers, and Velma Dinkley spotted glowing seaweed scurry along the beach and into a drain pipe. Scooby was told to get it, although initially afraid, he was bribed by Velma with a Scooby Snack. Scooby pulled it out to reveal that a mouse was underneath. The two fought over it until Scooby won, annoying the mouse.
- While not explicity confirmed, Rocky Point Beach could be retconned into being situated in Coolsville, the town Mystery Inc. grew up in as children as depicted in A Pup Named Scooby-Doo.