Troll

Troll is a movie starring Michael Moriarty, Shelley Hack, and Noah Hathaway. A wicked troll king in search of a mystical ring that will transform him to human form invades a San Francisco apartment complex where a powerful witch...
When a family moves into a San Francisco apartment, an opportunistic troll decides to make his move and take possession of little Wendy (Jenny Beck), thereby paving the way for new troll recruits, the first in his army that will take eventual control of the planet. We soon discover Torok is the ex-husband of Eunice St. Clair, a resident in the building who was married to Torok.