A Matamata’s most striking features are its head and neck region. Viewed from above, the head is a broad triangle in shape with a very long, slender snout forming one tip of the triangle. All along the head and long, muscular necks are small, multi-branched tufts or flaps of flesh. These loose tufts drift and sway with any current in the water or movement of the turtle, making the turtle appear as if it was covered with weeds or algae. The Matamata Turtle can weigh up to 27 pounds, making it one of the largest freshwater turtles. Females are generally larger than males. In adults the carapace is usually black or brown with some orange color, while the plastron ranges in color from a light yellow to a deeper brown shade. Each individual clamina (horny plate) can be fairly rough in appearance, due to the way that the clamina grows. Three keels run the length of the carapace; these keels result from the center of each clamina rising up to form a knob, with the highest knobs at the back of the carapace. The skin of the Matamata varies from an orange-brown to a gray-brown tone. The eyes of the Matamata are very small and situated very near the snout. This tends to
indicate they are of little value in capturing prey. The limbs are poorly developed.

Hatchling Matamatas are more colorful than adults. The carapace is light brown with a dark stripe running down the center, while the plastron is pink, as are the undersides of the juvenile’s limbs and throat. Three narrow black stripes run from the top of the head back along the neck. Usually there are a series of pinkish blotches on scutes along the edge of the carapace, with darker blotches on the more interior scutes. All of these juvenile colorations tend to darken or disappear as the turtle ages, however.