Troll

Trolls are mythical, magical creatures who live adjacent to the Enchanted Realm/Kingdom. They can be seen in Tween places such as windows and doorways. They come into existance in our realm at midnight

Trolls are evil, very fast, sneaky, vile little creatures who will do anything for a chance rule the Enchanted Kingdom; they are relatied to Gremlins. Don't be fooled, although very small, they are strong and cunning.

Their respective enemies are Fairies and other good magical beings who dwell within the Enchanted Kingdom.

Trolls appeared in the episode Once Upon A Time, holding Fairies captive and a few of them were vanquished by The Charmed Ones who could see them after being sprinkled with Fairy dust, and casting a spell cultivating innocence.