Holiday Super Sock monster.

Ok, on the first Holiday Super Sock monster I killed, it dropped some weird purple thing. But one thief took it, and wouldn't tell me what it was.
So I roamed all through the channels, killing them all but no purple thing dropped.
Just then, I killed another one and TWO purple things dropped, but a bowman looted BOTH of them and wouldn't tell me what it was.

So does anyone know what this 'Purple thing' is, and if it has any real value? (Or any other drops that have potential value.)


Also, I'd like to say; the Holiday Super Sock monster is poisonable.