Well if you include the large freedom breeder tub racks, then almost anything. All colubrids (kings, corns, milks, ratsnakes, bullsnakes, gophersnakes, garters etc etc) Pythons from anthill pythons to retics (the biggest freedom breeder rack tub is 96" long) boas.. almost anything.. there are even racks for arboreal snakes like green tree pythons and emerald tree boas.