My Green Fedora

Three years before the name Elmer Fudd first appeared on movie screens (and four years before his recognizable form debuted, as he started out as Egghead), the name Elmer was used for a baby rabbit in Friz Freleng's "My Green Fedora". This cartoon portrays a mother rabbit telling her oldest son to keep an eye on the baby while she's out, and so he tries to entertain the tyke with a riff on the title song, but a hungry wolf hears him singing and guesses that there's food in the vicinity. It leads to a quite impressive game of cat and mouse.

Apparently, this cartoon features a parody of an entertainer named Joe Penner. Unfortunately, I don't know who he was. So, I just take the cartoon at face value, regarding it as a look into Warner Bros. animation's early days. Available on YouTube.