Vampyres

According to many sources, Vampyres were to be implemented in Myth: The Fallen Lords, just like the Dirigibles, the Griffins, the Skrael, and the Spores. Vampyres had the temptation for human flesh, and they were to be called into battle by the Ghol Shamans. It's unknown if these bat creatures had any will of their own.

While the Myth world does include Skrael and Griffins in the lore, it is quite possible that Vampyres were to exist at one point, especially with the amount of bats flying around the Ermine and The Watcher's arm.