Celestial Unicorn

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

Brightmare

When Brightmare enters, tap up to one target creature. You gain life equal to that creature's power.

Eriette of the Charmed Apple

Each creature that's enchanted by an Aura you control can't attack you or planeswalkers you control.
At the beginning of your end step, each opponent loses X life and you gain X life, where X is the number of Auras you control.

Mesa Enchantress

Whenever you cast an enchantment spell, you may draw a card.

Mesa Unicorn

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

Possessed Goat

{3}, Discard a card: Put three +1/+1 counters on Possessed Goat and it becomes a black Demon in addition to its other colors and types. Activate only once.

Neighborhood Guardian

Whenever another creature you control with power 2 or less enters, target creature you control gets +1/+1 until end of turn.

Captivating Unicorn

Constellation — Whenever an enchantment you control enters, tap target creature an opponent controls.