Mairwen's hyperactive Weasel familiar. He should never be in charge of making decisions, as he will usually choose the wrong one. He is occasionally sent on tasks involving stealing things and spying on people. He is roughly the length of her forearm, not including his tail.
He's been traveling with Mairwen for so long he knows exactly the information she wants, and what kind of items she'd want him to steal (gold is preferred, always), and who he needs to be kept an eye on.
And he does this very well, actually. When he does it, that is. He isn't the smartest creature in the world, and he gets easily distracting by food, fun, or theft. He'll get back to his task eventually. Just a matter of... When.
He runs around a lot, even when he's trying to explain something, making it hard to follow him. He also "talks" very fast to Mairwen [through the 'Speak with master' skill], sometimes too fast for her to follow, and he has to stop and slow down and repeat himself.
He loves new people and especially other people's familiars and animal companions. He will climb all over people, and his favorite perch is on someone's shoulder. Or in Mairwen's hair (half of why she keeps it in a braid, honestly.)
If he likes someone, he will bring them things as well. (Including taking requests). And the easiest way to get him to like someone is either bring him food, or Mariwen trusting them.
He gets along with Garaja (Mairwen's mare), and will often rest on the horse's back and leave things in the saddlebags. He has a very sibling-esque relationship with Rata (her pet crow), however. They will steal each other's shiny things and get into small, playful "fights", but they work together seamlessly when it comes to Mairwen.
Mairwen uses his fur for paint/calligraphy brushes on occasion and he wraps around her neck when it's cold to keep her warm.