Wondrous Item, common
This wishbone must have come from quite the sizable goose -- it's large enough that an adult Human could hold one part of the fork in either hand.
You may use a bonus action on your turn to break the bone before attempting anything that requires a d20 roll. Replace that roll with a 50/50 determination -- the roll is either treated as a 1 (left hand) or a 20 (right).