30-50" (76-127 cm). Streamlined black body with greenish cast. Dart-shaped yellow spot occupies central area of each black scale; concealed front edge of each scale blue, exposed rear edge black. Black stripe behind eye. Scales weakly keeled, in 17 rows. Anal plate divided.
Breeding:
About 2-8 eggs, 1 1/2" (38 mm) long, are laid April to July; hatch in 2 months.
Habitat:
Dense theckets near water.
Range:
Extreme s. Texas south to Colombia.
Subspecies:
Four; 1 in our range, D. m. margaritiferus.
Rarely encountered north of the Rio Grande. Fast-moving and difficult to capture. Feeds on frogs.