A semi-sentient bag that squealed when removed from a pocket by anyone other than the wearer.

In The Hobbit, such a purse was in the posession of the stone-troll William Huggins, though whether he was its rightful owner, was not stated. When Bilbo tried to pick William's pocket the purse yelled "'Ere! 'Oo are you?" and Bilbo was caught. What became of the purse when William and his brothers turned to stone we are not told.