Open 20 gallon tank

Im just curious about what animal will do well in a 20 gallon tank. I made a thread last night but there weren't many people on and i didn't get any replies

A nice paludarium, with fire belly toads. I have a 40 gallon like that and its awesome.

for snakes all I can come up with are garters or cornsnakes. If it was me Id go with a female hognose.
Otherwise a pair of leos, fire skinks or any small skinks like berbers. I love fire skinks. Maybe some other exotic small lizard or gecko species.

Mice, hamster, gerbils. tarantulas.