The bush dog has partly webbed toes that help it swim, and it hunts cooperatively with its pack, keeping in touch through high-pitched calls in dense forest.
The glass frog has a see-through belly that exposes its heart, gut and eggs, while its green back matches the leaves where it rests above Atlantic Forest streams.
The male blacksmith tree frog molds a circular mud basin beside the river, apart from the current. The female spawns only when the structure shelters the eggs and tadpoles.
The tegu keeps flicking its forked tongue to pick up chemical particles from air and ground, then delivers them to the vomeronasal organ in the roof of its mouth. That scent map guides it to food and warns it of danger.
A structure on top of the green iguana’s head detects shifts from light to shadow, a warning of predators overhead. The reptile then escapes into water, while gut microbes ferment the leaves it eats.
The glass lizard looks like a snake at first glance, but its movable eyelids and its tail give it away. The tail can snap in several places, and the regrown version is shorter and made of cartilage instead of bone.
Known in Brazil as the two-headed snake, the amphisbaenian belongs to a group of its own. It digs with a compact skull, wears a ringed body and can move backward through a tunnel as easily as forward.
Threatened, the boipeva widens its silhouette, gapes and freezes, borrowing the look of a pit viper like the jararaca. The bluff works on sight alone, and it is not an invitation to handle the snake.
The dormideira, a slow, nocturnal snail-eating snake harmless to people, reaches into the shell with a long, narrow, asymmetric jaw and pulls the snail out without breaking it.
The rainbow boa shows its colors without a pigment for each hue: microscopic layers in the scales bend the light. On the ground at night, it hunts by constriction and gives birth to live young.
