It is a small gopher with gray fur.
It seemed interested in the corn husk doll's hat. It bit Scooby when he tried to get it back.
Scooby-Doo and the Witch's Ghost
The hat from a corn husk doll which Scooby-Doo tried on, blew off and landed next to a gopher hole. A gopher then popped up and took it back down with him. Scooby stuck his hand down trying to get it back, but was bitten by the gopher. Angered, he started digging, but only found what appears to be a shoe buckle.
- DTV2. Scooby-Doo and the Witch's Ghost (no lines)