What species of reptiles are fairly trainable?

are there any species of reptiles that are trainable? i.e. bearded dragons, monitor lizards, iguanas, turtles, tortoises, crocodilians, etc.? i've seen plenty of these cold-blooded animals be trained but what other reptiles are trainable? if you know of any? and can snakes be trained as well? i've read something online can't remember what it was about someone saying that they've called there pet snake to come to them when called and that when they pat the ground the snake will come up slithering towards them, so i'm uming snakes are trainable and i'm aware that snakes don't have eardrums but have something called a inner-ear or something like that and feels vibrations from the ground and i've also read in a lot of snake books and online that snakes can actually hear a bit of airborne sounds and ground vibrations, so i'm aware of that but what species of reptiles or amphibians are trainable? and i've heard of people potty-training their iguana too!