Roalesk, Prime Specimen

Flying
Whenever Roalesk, Prime Specimen or another permanent you control is turned face up, you may pay {X}. If you do, if X is 1 or more, conjure a duplicate of a random creature card with mana value X into your hand. Cloak it. It gains "{G/U}: Turn this creature face up" for as long as it remains face down.
Disguise {G}{U}