Charun was the Etruscan psychopomp - the god in charge of escorting souls into the afterlife (called Aita.)
His name is derived from his Greek equivalent Charon, ferryman to lost souls. Despite this shared etymology, the two were decidedly different in appearance and function. Charun was most commonly portrayed as a beast-like man, with pointed ears, a heavy beard, sloping brow, and discolored skin. He also sported snakes which encircled his arms. He's a fairly heavy metal sort of deity.
To complement his fairly brutish countenance Charun's main characteristic was his large hammer. Although the hammer was considered a good talisman to ward off evil spirits, Charun's mythology quickly evolved so that the hammer became a weapon of torture and destruction. Late Etruscan and post-Etruscan portrayals of Charun sometimes have him riding on horesback carrying both his hammer and his sword, wielding them as brutal herding instruments against his flock of dead souls.
Charun was said to enjoy war and natural disaster, and became known for appearing at the end of battles to separate the brave warriors of the day from the cowards, who were given special punishment in the beyond.
The concept of Charun was later distilled into a group of death demons called Charontes, generally serving the same purpose but with even more malice.