Midnight entity
From Tardis Wiki, the free Doctor Who reference
During the Crusader Tour to the Sapphire Waterfall, a strange monster attacked the tour bus. The monster knocked on the Shuttle and then possed Sky Silvestry and The Doctor, who both managed to escape from the possession.
Unique to Doctor Who, you didn't see the monster and the Doctor didn't defeat it, so it is still loose on Midnight.
