Cooked turkey drumsticks can be obtained by cooking a raw turkey drumstick, which is a drop from turkeys and angry turkeys. They heal 200 Lifepoints when eaten. Turkeys were around in the 2008 Thanksgiving event, and angry turkeys appeared during the 2011 Thanksgiving event. Both also dropped raw turkeys.
This is a different item from the turkey drumsticks found during the 2009 Christmas event, which healed only ten Lifepoints.
If you eat the drumstick it will display "You eat the turkey", even though it's only a drumstick.