On the show? I'm guessing she's Mab as in Queen of the Faeries aka the original witch*.
*if you're the sort that believes in witches or faeries, obviously
hmm.. maybe, or at least it's probably a reference to it.
Sad that I watched a few episodes but can't remember the character Mab, lol. If she's a witch, chances are she was either named for Mab or adopted the moniker in her honor, Mab is the dark counterpoint to Titania.
He used to go by "C.T." even though his middle name doesn't begin with a T (nor does his last). Like CoTton, I suppose. He eventually embraced the touch, the feel of his real name and used it instead.