Sanguine Syphoner

Whenever this creature attacks, each opponent loses 1 life and you gain 1 life.

Cat Collector

When this creature enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you gain life for the first time during each of your turns, create a 1/1 white Cat creature token.

Swamp

Fiendish Panda

Whenever you gain life, put a +1/+1 counter on this creature.
When this creature dies, return another target non-Bear creature card with mana value less than or equal to this creature's power from your graveyard to the battlefield.

Tribute to Hunger

Target opponent sacrifices a creature of their choice. You gain life equal to that creature's toughness.

Temple of Silence

Temple of Silence enters tapped.
When Temple of Silence enters, scry 1.
{T}: Add {W} or {B}.

Hinterland Sanctifier

Whenever another creature you control enters, you gain 1 life.

Sun-Blessed Healer

Kicker {1}{W} (You may pay an additional {1}{W} as you cast this spell.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, if it was kicked, return target nonland permanent card with mana value 2 or less from your graveyard to the battlefield.

Dazzling Angel

Flying
Whenever another creature you control enters, you gain 1 life.

Moment of Craving

Target creature gets -2/-2 until end of turn. You gain 2 life.

Inspiring Overseer

Flying
When Inspiring Overseer enters, you gain 1 life and draw a card.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.

Vengeful Bloodwitch

Whenever this creature or another creature you control dies, target opponent loses 1 life and you gain 1 life.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Healer's Hawk

Twinblade Paladin

Whenever you gain life, put a +1/+1 counter on Twinblade Paladin.
As long as you have 25 or more life, Twinblade Paladin has double strike. (It deals both first-strike and regular combat damage.)

Vampire Nighthawk

Plains

Scoured Barrens

Scoured Barrens enters tapped.
When Scoured Barrens enters, you gain 1 life.
{T}: Add {W} or {B}.

Mortify

Moment of Triumph

Target creature gets +2/+2 until end of turn. You gain 2 life.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.