Muggles' Guide to Harry Potter/Characters/Mulciber

Overview
Little is known about Mulciber. He is mentioned as being particularly good at performing the Imperius curse.

Goblet of Fire
Igor Karkaroff, pleading for early release from Azkaban, says that Mulciber specialized in the Imperius curse, making his victims do horrific things. Bartemius Crouch Sr. dismisses this information, saying they have already caught Mulciber.

Order of the Phoenix
We assume that Mulciber was among the Death Eaters to escape from Azkaban midway through the novel: though he isn't mentioned by name, his presence later on implies such. Mulciber later takes part in the battle of the Department of Mysteries. When the Death Eaters split up he goes with Lucius Malfoy to search and is not known to have encountered any of the students during the chase. He later takes part in the final battle where he is presumably defeated and sent back to Azkaban.

Half-Blood Prince
When Lord Voldemort, or Tom Riddle as he is then known, is seen in Albus Dumbledore's memories returning to Hogwarts to apply for the job of teacher of Defence Against the Dark Arts, Dumbledore asks him about his "friends" waiting for him back in Hogsmeade. Mulciber is one of the friends named, along with Nott, Antonin Dolohov, and Evan Rosier.

Deathly Hallows
Mulciber was mentioned by Lily Evans, seen in Severus Snape's memories in the Pensieve, as being one of the people that Snape hung around with that Lily simply could not stand.

Strengths
Mulciber is said to be skilled with the Imperius Curse.

Analysis
If Mulciber is one of Snape's crowd, he must be about the same age as James Potter; however, we know that the Potters were born when Voldemort was about thirty. Voldemort had carefully selected four of his cronies, who were then starting to call themselves Death Eaters, to accompany him to Hogwarts to ask for the Defence Against the Dark Arts job. Given that by the time James died, the Wizarding world was terrified of the Death Eaters, Voldemort's application must have been some time before James' death, when any friend of Snape's would have been still very young. It is unlikely that Voldemort would have brought someone as young as that into his inner council. It is entirely possible that there are two Mulcibers, probably father and son, and they are not differentiated in the books. Since neither Mulciber is fully named (in the British convention, people are often named by surname only) it is difficult to know which one is being referred to most of the time.