Tree for Two (1952)

A rough and tough bulldog named Spike sets out with his admirer, a small dog named Chester, to rough up a cat. They encounter Sylvester and chase him into a junkyard, where a black panther that escaped from a zoo just happens to be hiding out. Every time Spike goes into the junkyard to thrash Sylvester, he is clawed into pieces by the panther, which he, in a dark maze of crates, thinks is Sylvester. Chester has no problem pummelling Sylvester before Spike's eyes, which convinces Spike that Chester must be tougher than him.