Ptyas carinata, commonly known as the keeled rat snake,[2][3] is a species of colubridsnake. It is found in Indonesia, Myanmar, Malaysia, Thailand, Philippines, Cambodia, India, Vietnam, Laos and Singapore.[4] This little known species is probably the largest extant species in the diverse colubrid family that includes just over half of living snake species. Known adult lengths of snakes of this species in Taiwan measured anywhere from 1.21 to 2.75 m (4 ft 0 in to 9 ft 0 in).[5] However, the reportedly maximum size was about 4 m (13 ft 1 in).[6] Males reportedly average slightly larger than females.[7] They are probably opportunistic predators on a variety of prey, such as rodents, though adult lizards are thought to be significant prey in Indonesia.[8]