Holy Cow

Flash
Flying
When this creature enters, you gain 2 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Thriving Heath

This land enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Healer's Hawk

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

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on this creature.

Nyx-Fleece Ram

At the beginning of your upkeep, you gain 1 life.

Plains

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.

Fierce Retribution

Cleave {5}{W} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Destroy target [attacking] creature.

Makeshift Binding

When this enchantment enters, exile target creature an opponent controls until this enchantment leaves the battlefield. You gain 2 life.

Vanguard Seraph

Flying
Whenever you gain life for the first time each turn, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Felidar Savior

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, put a +1/+1 counter on each of up to two other target creatures you control.

Nykthos Paragon

Whenever you gain life, you may put that many +1/+1 counters on each creature you control. Do this only once each turn.