1: A shark (depending on type) would beat a crocodile on tactics. Crocodiles kill their prey by drowning them. Wouldn't work on a shark unless by accident (as a shark needs to move to breathe).
2: Depends on territory. But I suspect the bear. However, a bear in say Egypt, might lose due to exhaustion from overheating, and lack of honey.
3: Almost certainly the Elephant. The Anaconda has to use multiple coils in order to crush it's prey, and is likely to only manage a maximum of say 2 on an Elephant. However, the likelihood of this match ever happening is rare: no Anaconda would choose a prey the size of an Elephant, and the Carthaginian War Elephant died out centuries ago, so there are no longer any Elephants looking to pick a fight
1 Shark vs. Crocodile?
2 Bear vs. Crocodile?
3 Anaconda vs. Elephant?