Creeping Bloodsucker

At the beginning of your upkeep, Creeping Bloodsucker deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Pest Summoning

Create two 1/1 black and green Pest creature tokens with "When this creature dies, you gain 1 life."

Quiet Disrepair

Enchant artifact or enchantment
At the beginning of your upkeep, choose one —
• Destroy enchanted permanent.
• You gain 2 life.

Cast Down

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Blood Researcher

Menace (This creature can't be blocked except by two or more creatures.)
Whenever you gain life, put a +1/+1 counter on Blood Researcher.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Hunt for Specimens

Create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Unmake

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Forest

Golden Urn

At the beginning of your upkeep, you may put a charge counter on Golden Urn.
{T}, Sacrifice Golden Urn: You gain life equal to the number of charge counters on Golden Urn.

Swamp

Seed of Hope

Mill two cards. You may put a permanent card from among the milled cards into your hand. You gain 2 life. (To mill two cards, put the top two cards of your library into your graveyard.)

Infuse with Vitality

Until end of turn, target creature gains deathtouch and "When this creature dies, return it to the battlefield tapped under its owner's control."
You gain 2 life.