The Mirror

"The Mirror" is the eighteenth episode of Gargoyles, and the thirteenth single-part episode of the series.

Plot
A magical mirror is stolen by Demona who frees the mischievous Puck from it; purposely re-interpreting Demona's wishes, he makes the Gargoyles human and the humans gargoyles. In the chaos Goliath and the others are able to detain him and send Demona fleeing, but as a gift for the fun he'd had, Puck grants Demona to become human during the day instead of her vulnerable stone sleep.