An Owl Conjuring Hex is an incantation that conjures "an endless column" of "hooting and screeching" "black owls" that can be directed toward an opponent. The incantation is currently unknown, but the Hex may be a variation of the Avis Spell.
Diana Grimm used the Hex in a duel against Abraham Thorn at the Thorn family crypt on Croatoa during the Summer of 2010.