The Mitre of Saint Mullet

This simple, onion shaped hat was once worn by the holy man known as St. Mullet. When worn by priests of a similar alignment (GM's choice)it conveys a medium bonus while casting spells and resisting magic.
If the hat is worn consistently for more than a week, the wearer will discover that the hair in at the back of their head is growing at an accelerated rate (but will return to normal growth in about three days/hair extends 5 inches). After two weeks, the bonuses are present even when the mitre is not worn.

However if the new hairstyle is not maintained, the bonus is lost when the hair is cut or grows out (approx 1 month).