The Trapeze Artist is a 1934 short animated film by Columbia Pictures, starring Krazy Kat.
When the judge asks him about the incident at the circus, Krazy explains in song how he tries hard to be a proper date with the mink as well as the struggles her family have in making her his bride.
Upon getting back up, the acrobat takes a large piece of lumber, and aims to assault Krazy.
Krazy, using a shovel from the room, scoops some burning coals from a stove and pours them into the acrobat's trousers.
Some scenes showing the burning coals from the stove and the one that Krazy, using a shovel from the room, scoops the burning coals from the stove and pours them into the acrobat's trousers, in the black and white copies of the short (original version), for some reason, were censored, but the 70's redrawn color version normally shows them.