Fast, friendly, fearless, and holding something that isn't theirs.
Often a Cocker Spaniel, Labrador Retriever or Bengal, though every pet is its own animal.
The Sock Thief runs on speed, company and nerve, and would rather play than eat. If something can be carried, it is being carried. If someone new arrives, they are a friend within the minute, and they will be shown the sock.
First out of the car, first to every dog, and somehow already wet.
Never more than one room away, usually with something of yours.
Loves them all, forgets to check whether they feel the same.