The plains western hognose snake (Heterodon nasicus) can be recognized by the sharply upturned snout. When threatened the snake will flatten its head, inflate its body with air, and his loudly to intimidate the intruder.
If this show proves unsuccessful, the hognose snake will turn over on its back and play dead. If the snake is turned upright it will again roll over and continue trying to convince its antagonist that it is dead.
Snakes - Plains Western Hognose Snake