Cuniculus snakes are burrowing snakes native to Robus Island, on Saaristo.
They reach five metres long. Their colouration is white with grey splotches, to blend in with the snowy environment on Robus.
They have special water-resistant eyelids to protect their eyes when burrowing, and they can seal their lips extremely tightly. When burrowing, they use echolocation to detect potential obstacles. In addition to these adaptations, it also has a head wider than the rest of its body, so once it has cleared the way, the rest of the body can follow easily.
They are solitary except for when they get together to mate. Eggs are laid in clutches of three to six. The eggs are normally pure white, and hidden in snow. After this, they are abandoned, and must grow up alone, or with other hatchlings.
Cunuculus snakes have a diverse diet. Their primary food source is smaller creatures, but if these are in short supply, it can also survive on snow.
They live on the snow-covered island of Robus.