The genus Philodryas consists of about 15 species. They are all rear-fanged and some species can pack quite a punch as far as toxicity. They mainly eat lizards and frogs as you said, but can be switched to mice. They get up to about 4 feet long or so. They like it warm and humid,. typically, but depends on which species you have. Ask about these on the rear-fang forum and you'll probably get more answers.