Skeletal wyvern tail-bone

The skeletal wyvern tail-bone is an item on the Odd Old Man's wishlist after the Fur 'n' Seek quest, and is dropped by Skeletal Wyverns. It shouldn't take more than 20 kills to get a bone drop. 8 other tail bones are needed from green dragons, blue dragons, black dragons, red dragons, bronze dragons, iron dragons, steel dragons, and mithril dragons to complete this miniquest.