Geographic range: Neotropical: Found from S USA through Mexico south to Costa Rica. In Mexico on both coasts, on Pacific side from Arizona and on Atlantic side from Tamaulipas south. Also on Yucatan peninsula.

Physical characteristics: Medium -sized, quite slender snake (75 - 100 cm). Head moderately narrow, distinct from neck. Pupils round, eyes small. Scales on upper body weakly keeled, on sides smooth. Color pattern very variable throughout the range! In some regions no obvious pattern present and body color from greenish, olive to gray or even red. In other geographical areas rectangular blotches on upper body and sides, usually lined with black. Dark, crescent shaped blotch usually present on upper surface of the head. Underbody usually cream or white.

Food habits: Small mammals (also bats) and occasionally birds.

Reproduction: Oviparous. Reproduces possibly throughout the year. Typical clutch 3 -7 eggs.

Behavior: Terrestrial, nocturnal.

Habitat: Variety of forested habitats and dry scrub.