Moonlight Sleepcaster

Flying
When Moonlight Sleepcaster enters the battlefield, target opponent falls asleep.
(Phases out until the turn after their next.)
Whenever Moonlight Sleepcaster deals combat
damage to a player, that player falls asleep.
They silently lurk in the moonlight at night and sing a melody that makes any unsuspecting traveler fall into
a deep, dreamless sleep.