Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Mesa Unicorn

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

All creatures able to block Prized Unicorn do so.

Whenever Inspiring Unicorn attacks, creatures you control get +1/+1 until end of turn.

Whenever another creature you control enters, put a +1/+1 counter on that creature.

Sacrifice Ronom Unicorn: Destroy target enchantment.