Tales of Tolgard
The wyvern’s spur is literally a mummified “wyvern’s spur” (a talon). It is no larger than a zucchini and uglier than a three-week-old sausage. The spur was bestowed generations earlier to Paton, the founder of the family line, by a grateful wyvern whose spirit then remained as an entity known as the Guardian. In recent years the spur has come to be known more as a family heirloom than its qualities as a magical artifact.
The spur confers the ability to transform into a large wyvern as well as immunity to magic. It can only be wielded by a member of the Wyvernspur line and even then its powers can only be harnessed by a chosen member. A chosen or “favorite” is designated by the Guardian roughly once each generation.