Darahir

Darahir is an undead elf found at the Black Market in the Underbelly of Dalaran. He sells a Ghostly Skull companion in unlimited supply. During the purge of Dalaran, he was cowering in fear on the back crate.

Speculation
It is commonly believed that he is, infact, a former San'layn. It is noted that all Northrend NPC's using the same skin are San'layn.

It is also possible that he is a deceased former occupant of Dalaran, who resides now in the Underbelly. Possibly, he is shunned for his use of dark magic or even necromancy, as he sells floating skulls, and is dressed in robes that suggest his unusual profession; the Dreadmist Raiment.

Judging by his voice files, he appears to have been a high elf in life. The same voice files are shared with high elf NPCs, and also the male counterpart of the current dark ranger's voice used in Wrath of the Lich King, which is an edited version of the night elf NPC voice.