My Ghost Dog (1997)

He's cute, he's furry and he's completely invisible - except to Toby, his 8 year old best friend. His name is Lucky, The Magic Dog. When Toby's evil Aunt Violet tries to steal Toby's inheritance, Lucky fights off 2 teenage bullies and wrecks Aunt Violet's nasty scheme. Only you and Toby can see his invisible friend when Lucky saves the day.