Appearance:
Name: Gorschilthextreeb (Usually just Gor for short)
Race: Shoggoth (Here's the link if you'd like details,
http://monstergirlencyclopedia.wikia.com/wiki/Shoggoth, but the tl;dr is that they're a slime-girl-ish servant race that can shapeshift to be useful and will ultimately try to form a symbiotic bond with their master. Oh, and they
literally get off on serving people.)
Magic/Abilities/Equipment: Gor has nothing unusual for her race, she's a slime, which makes her difficult to injure, and her body can be changed into useful forms (a towel, a spoon, a toothbrush, a pair of clothes, a sword, etc.) but these are limited by the amount of matter in her body and the fact that she only has any real experience making household items. In addition, if she serves a particular person for long enough, said person will slowly start to gain minor slime-like powers (mainly regeneration, perhaps some minor shapeshifting if it goes on for long enough). As for equipment (or any possessions at all), f*ck 'em. She deliberately refuses to gather anything for her own use, her body will work just fine.
Personality: Overwhelmingly, almost offputtingly friendly. She's always eager to lend a hand to anyone (or a foot as need be (ba dum tss)). She obviously has kind of an ulterior motive (y'know, friendly people get to stay around humans, if you're around humans you're more likely to find a master, etc.) but she doesn't do it
because of that, it's merely an incidental benefit.
Background: It is possible for a shoggoth to simply appear before someone they would like to serve and immediately submit themselves to them, and that's kind of what happened with Bartholomew. She appeared at his side, gave her whole, "I will serve you until the day I die," speech, and eagerly awaited for him to accept her as a servant, but he did something a little different; he instead chose to hire her, instructing her that her loyalty was not to be to him, but to the guild itself. She took this in stride, and is now eager to help the guild grow and prosper... Perhaps once it's a success Bartholomew will decide a personal servant will be more valuable... But, no time for that now, there's work to be done!
Favorite Monster Girl (to prove I read the rules): Well, it's actually kind of a toss up between Shoggoths and Yetis, but ultimately I'd have to go with the lovely little servile slimes in this case.