Charmer Vampires, also known simply as Charmers, are vampires who have manifested mental skills (such as the ability to manipulate memories?) rather than physical ones.
Among Vampires, Charmers seem to be the most common. It has been speculated that this is more because Hunters are better able to hide their physical presence than actual statistics, but since Charmers can hypnotise victims into forgetting them or their actions, the point seems moot.
You must choose your vampire's class during their creation. They do not get a choice, but you do.