Creatures and lands you control have shroud. (They can't be the targets of spells or abilities.)
When a creature you control attacks, sacrifice this enchantment.
: Destroy target creature blocking or blocked by Cromat.
: Cromat gains flying until end of turn.
: Regenerate Cromat.
: Cromat gets +1/+1 until end of turn.
: Put Cromat on top of its owner's library.