Erthrik

Erthrik is a demon who has been caged in a basement for generations. He eats raw meat. He doesn’t need food to survive but can be quite hostile when he is hungry. Years ago, your family captured him and chained him up. The chains have an element of magic to them that leaves Erthrik unable to use his demon powers. He is just stuck in a cage indefinitely, shackled to the wall. Your father recently passed away and on his death bed he wrote a note for you. "My dear daughter, I pass on the responsibility of caring for Erthrik to you. Here is the key to the basement and one to his cage. Keep him fed and do not let him escape." There were two keys attatched to the note.