Flop Secret(1951)

Litle Rocquefort, the mouse named after a cheese, is reading a horror book to his cat pal. A Dr. Jekyll/Mr.Hyde-type character is mixing his evil potion, and needs the tail of a black cat and chooses the one on Roquefort's buddy. The mouse comes to his rescue, and when Dr. Silvana ropes the cat's tail, Roquefort uses his tail to make an electrical short-circuit. After a few more harrowing chases, the mouse finally rescues the cat. The cat's finale act if to make Little Roquefort eat the book.