Some of the things Tex Avery’s known and lauded for were invented before Avery ever became a cartoon director. But, if I may venture an opinion, he perfected them.
In the Ub Iwerks cartoons “Movie Mad” (1931), a Western bad guy’s eyes pop out. Not as exaggerated as Avery took it, but the concept had to start somewhere. This would have been pretty far out for 1931.
There were a couple of cartoons where Avery had his characters running in and out of doors on the left and right sides of the frame. The idea may have come from a French bedroom farce on stage for all I know, but Iwerks uses it in this cartoon. It’s not at the blinding speed as in Avery’s “Little Rural Riding Hood” (released in 1949) but this may be the first time it was used in a cartoon. To watch Flip take his time and then bother to close the door behind him is a little painful, it’s so slow.
No one other than Iwerks is credited on the cartoon.