The Magilla Gorilla Show S01 E06 Small Change

Mushmouse decides to sneak into the kitchen for a snack. When he opens the door to the icebox, he discovers that Punkin’ Puss patiently waiting for him. Mushmouse turns to a spell book to grow as big as Punkin’ Puss. The formula has the opposite effect and shrinks Punkin’ Puss to his size. Mushmouse decides to wreak havoc on his cat friend.