Atractaspis are also called mole vipers, burrowing asps, burrowing adders, stiletto snakes, or side-stabbing snakes. They can bite without opening their mouths!
Burrowing asps have a highly reduced dentition, with just two particularly elongate maxillary fangs (up to a third of total skull length), two short, gently curved dentary teeth, and a couple of very small palatine teeth[...}. The maxillary fangs (there are two in each maxilla, one of which is a replacement tooth kept in reserve) are huge compared to the short, block-like maxilla: in fact virtually its entire length is occupied by the transversely arranged fang sockets. The maxilla articulates with the relatively immobile prefrontal by way of a saddle-shaped joint (this contrasts with the condition in viperids, where the articulatory surfaces between the maxilla and prefrontal are flat), allowing the maxilla to easily rotate posterodorsally and anteroventrally.
Rotating teeth? I didn’t need to hear that! These snakes burrow underground and live in Africa and the Middle East. Link