What a Lion! (1938)

The Captain and Inspector are hunting lions in Africa, though their attempts to sneak up are hampered by alarm clocks and squeaky shoes. Fortunately, there's a lion ready for them: it's the boys, dressed in a lion costume, with an "ah-ooga" horn for the roar. They're soon chasing the Captain, when their costume gets stuck and pulled off. The captain comes in to the costume after them, but the boys manage to tie him up. Before long they've run into a real (sleeping) lion. They provoke it (in costume), and get its head stuck in a hollow log. Then they go taunt the Captain again and bring him over to the log, where the lion is still stuck; he whacks it with a board and pulls it out, then tries to remove the costume when the boys walk up behind him. The inevitable chase starts slowly, then speeds into a cave.

Unfortunately the movie What a Lion! is not yet available on HBO Max.