Kazandu Nectarpot

Landfall — Whenever a land you control enters, you gain 1 life.

Pristine Talisman

Avacyn's Pilgrim

Forest

Celestial Unicorn

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

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Plains

Jaddi Offshoot

Defender
Landfall — Whenever a land you control enters, you gain 1 life.

Light of Hope

Choose one —
• You gain 4 life.
• Destroy target enchantment.
• Put a +1/+1 counter on target creature.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Traveling Minister

{T}: Target creature gets +1/+0 until end of turn. You gain 1 life. Activate only as a sorcery.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Llanowar Elves

Revitalize

Soul Warden

Whenever another creature enters, you gain 1 life.

Impassioned Orator

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

Invoke the Divine

Destroy target artifact or enchantment. You gain 4 life.

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Trelasarra, Moon Dancer

Whenever you gain life, put a +1/+1 counter on Trelasarra, Moon Dancer and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Healer's Hawk

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