Fell Beast
The Return of the King #57 (x2/x1)
Traición
Morgul.  

When Revealed: Attach to a Nazgûl enemy. Limit 1 per enemy. (Counts as a Mount attachment with the text: "Attached enemy gets +1 Threat, +1 Attack, +1 Defense and -10 engagement cost. Forced: At the end of the round, return attached enemy

...horrible as carrion-fowl yet greater than eagles, cruel as death. -The Return of the King