Scorpionfly

 

This unusual looking fly with a long beak for mouthparts is called the scorpionfly (Panorpa communis), not because it stings (it's completely harmless), but because the male has a posterior protrusion that resembles a scorpion tail, the orange convolution of which is vaguely visible between its wings.

Apparently the male clasps the female on his back so his appendage can curl up and into her ovipositor for fertilization.

Their elongated mouthparts enable them to feed on fresh decaying plant and animal matter. Forensic entomologists know that if scorpionflies are present on a cadaver, it's still relatively fresh, 1-2 days old.