I have a 20 gallon long tank but I'd like to put a new reptile or amphibian in. I have reptiles already being, three ball pythons, a crested gecko, and African sulcata tortise, and three water turtles. I just have this 20 gallon tank sitting here and I'd like to put some sort of reptile or amphibian it in that can stay there for the rest of their life. I like exotic stuff. Any suggestions?