She was portrayed by Deborah Reed.
Creedence is the queen of the goblins (depicted in the film as an evil race of human and vegetable eaters who want to feed humans magic green slime that kills them and turns their dead bodies into their favorite food, human vegetable slime). She and the other goblins live in the goblin kingdom of Nilbog ("Goblin" spelled backwards) where they trick humans into thinking that it is a town that they can stop and visit so they can eat them. All the goblins disguise themselves to look and talk like humans, with Creedence herself taking the form of a creepy old lady, though they can exit their disguises at any point and they go away when the goblins die.
When the human characters arrive Creedence and her minions pretend to befriend them, with Creedence getting them to believe she is Nilbog's head witch doctor and a nice albeit eccentric old lady.
When the main character Joshua discovers the truth about Nilbog and how the inhabitants are not human, she tries to kill him (though he escapes her and warns his family), and successfully kills two of his sister's boyfriends friends and tries to kill the third friend by using all of her magic to transform her (human) appearance into that of a sexy beautiful young seductress (with large cleavage and a low cut skirt revealing black panties underneath) so she can trick him into letting her in so she can kill him, but rather than just eat him, she casts a spell on him and leaves him to drown to death in popcorn while she and the other goblins go kill the five remaining humans.
Joshua (with help from the ghost of his dead Grandpa Seth) discovers the only two weaknesses of the goblins: they can not hurt someone for a short while after they have eaten meat and if their magic stone is touched by a human they will all die. Creedence dies when Joshua combines these two advantages to become immune to her magic so he can easily touch the stone and destroy all the goblins. Creedence was killed just in time, as the third friend was just seconds away from death, when she died the popcorn disappeared.
At the end of the movie, Joshua's mother is eaten by goblins (despite what Grandpa Seth said), suggesting that a small number of them must have survived and made their way to his home, though it is confirmed that Creedence was not one of the survivors.