This slightly scary insect posing for me is a Gasteruption jaculator. As far a I know, it doesn't have a common name. It is widespread in Europe, but fairly rare.
Olympus XZ-1, 28mm, ISO320, f4, 1/80s
The females of this species lay eggs on the larvae of solitary bees and wasps.
After hatching its larvae will eat the nearby eggs and bee larvae and then the supplies of pollen and nectar of their victims, so it's not a very nice animal if you like bees.