Mensis Corridor

{t}: Add {u}.

{t},{1}{u}: Target creature becomes tapped
unless its controller pays {2}. If the creature is tapped this way, create a 1/1 colorless Skeletal Puppet creature token, otherwise put a Madness counter on the target creature.

If this card is in your hand, it is a Instant.
You can pay {1}{u}, trigger its second effect.