Gresilda is the main antagonist in The Haunting Hour: The Series two-part episode "The Most Evil Sorcerer".
She was portrayed by Gina Holden.
Gresilda is an evil sorceress who used to be Margolin's apprentice, until she challenged Margolin to a magical duel. Gresilda had lost the battle and was left trapped inside the forest of timrod. Gresilda was first shown saving two siblings named Sara and Ned from a beast as an old creepy woman. She revealed that her creepy disguise was used to scare off enemies and intruders.
When Sara had removed Margolin's amulet from his neck, Gresilda was free and was ready for another battle/fight with Margolin, but without his amulet, Margolin's magic was useless and was transformed into a dung beetle by Gresilda.
After Gresilda had released Margolin outside as a dung beetle permanently, she started to act like Margolin himself (but worst). Gresilda was then tricked by Ned into smelling a sleeping potion then Ned remembered the spell that Gresilda was performing (when his eyes were taken away and were being put in a jar right next to her.) and had put Gresilda into a deep sleep, but Sara revealing that a kiss can break the spell. 100 years later Gresilda was still under the sleeping spell until an unnamed male hiker came up thought something was wrong with Gresilda and started to give her CPR. Gresilda woke up furious and shocked the unnamed male hiker.