Crypto, Nightmarish Beast

Shadow (This creature can block or be blocked
by only creatures with shadow.)

When Crypto, Nightmarish Beast enters the battlefield, create three 2/1 Nightmare creature
tokens with "When this creature deals combat
damage to a player, target creature has a dream.
(That creature is tapped and doesn't untap until its controller takes damage.)
At the beginning of your upkeep, destroy
target tapped creature.