Devil's coach horse beetle

It is a long-bodied beetle. At about 25–28 millimetres (1.0–1.1 in). Its wing covers (elytra) are short covering only its thorax, exposing the abdominal segments. The abdominal musculature is powerful and the abdominal segments are covered with sclerotized plates. It is capable of flight but its wings are rarely used. It is covered with fine black hairs.
It is well known for its habit of raising its long and uncovered abdomen and opening its jaws, rather like a scorpion when threatened. This explains one of its alternative names, the cock-tail beetle. Although it has no sting, it can give a painful bite with its strong pincer-like jaws. It also emits a foul smelling odour, as a defensive secretion, from a pair of white glands at the end of its abdomen. (wikipedia)