He is a Death Eater. Death Eaters are fictional characters in the Harry Potter series of novels and films. They are a group of wizards and witches, led by the dark wizard Lord Voldemort, who seek to purify the Wizarding community by eliminating the Muggle-borns (wizards or witches born to non-magical parents). They also try to create a new order through the Ministry of Magic and spread fear throughout the Wizarding community by terrorising and killing important officials and other enemies of the Death Eaters, chiefly the members of the Order of the Phoenix. Although the reason why they are called "Death Eaters" has not been explained by J.K. Rowling, there is some evidence to suggest that it is a reference to their ultimate goal of preventing death and achieving immortality.[2][3]

Death Eaters recognise one another by the Dark Mark on their left forearm, a sign created by Voldemort to summon him instantly to them or vice versa. Their typical attire includes black hooded robes and masks. The Death Eaters, as a group, first appeared in the novel Harry Potter and the Goblet of Fire, although individual members of the group, such as Lucius Malfoy, Peter Pettigrew, and Severus Snape, had appeared in earlier books in the series. And he is Evil.