I used to be such an avid collector of reptiles and occasionally amphibians -meaning that I would habitually catch 'n' release live prey- that almost half a century later my family still regards me as an expert on identifying these critters. These look like spadefoot toads. It's been a while!
Almost every species of snake and lizard in my state. If you mean, 'what [live food prey?] they were fed once captured?', well there were bugs in light traps and mice from pet stores and so on.
Oh in the OP. That's a very noxious kind of caterpillar. Were a human to so much as touch they would be stung badly. It looks like a small yellow fiddler crab. A toad could believe it or not stomach a crab.
