Demona, voiced by Marina Sirtis, is a fictional character and one of the primary antagonists of the Disney animated television series Gargoyles. Demona was once Goliath's mate and was part of their 10th century AD castle's Wyvern Clan. She is consumed by a hatred of humanity and has attempted several times to destroy it.

Marina Sirtis is a British actress. She is best known for her role as Counselor Deanna Troi on the television series Star Trek: The Next Generation and four Star Trek feature films, as well as other appearances in the Star Trek franchise.