Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is the first in a series of 12 Tarzan movies Johnny Weissmuller made between 1932 and 1948. I suspect that each one, along with all of the jungle movies he made after them as the character "Jungle Jim" had at least one scene with a crocodile. It just wouldn't be a jungle adventure movie without a crococile.
Everybody knows the story - Tarzan is a white man who wears only a loincloth and lives alone in the jungle up in a tree with a group of apes, or at least he does before he meets Jane. He talks to elephants and uses them to help him, steals meat from the lions then outruns them, kills leopards single-handedly with just a knife, and even gets help from hippos, but for some reason, he can't quite gain the cooperation of crocodiles. This is the movie where he kidnaps Jane and the Tarzan universe is established - we see lots of cut-aways to file footage, and rear-projections, of wild animals that look like they were filmed years earlier and thousands of miles away from that what we are watching on screen (because they were). We see exotic-looking African tribesmen whose part in the movies is mostly to carry stuff, to die in accidents, and to fight with the whites, and we see plenty of pith helmets and Khaki-wearing bwanas - white hunters who are in the jungle for dubious reasons.
In the first crocodile scene, before we meet Tarzan, some white hunters and African tribesmen are searching for the elephant's graveyard to collect the ivory. They're crossing a Hippopotamus-infested river on two make-shift rafts when one of the rafts is destroyed by a hippo. This prompts a bunch of crocodiles to jump in the water. One guy doesn't make it on to the raft. He gets munched by one of the big rubber crocodile contraptions they used when they weren't showing file footage of wild crocodiles or zoo crocodiles. Another is grabbed when he tries to get to shore. Jane screams in terror at the carnage - which we see in stock footage of a crocodile eating something.
In another crocodile scene, Tarzan is pursued by some crocodiles ( fake ones again) so he jumps on the back of a hippopatamus to get to the shore safely.