Necrotic Fumes

As an additional cost to cast this spell, exile a creature you control.
Exile target creature or planeswalker.

Jungle Hollow

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

Riveteers Overlook

When Riveteers Overlook enters, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Essence Warden

Whenever another creature enters, you gain 1 life.

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Witherbloom Campus

Witherbloom Campus enters tapped.
{T}: Add {B} or {G}.
{4}, {T}: Scry 1.

Basic Conjuration

Look at the top six cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. You gain 3 life.

Witherbloom Apprentice

Magecraft — Whenever you cast or copy an instant or sorcery spell, each opponent loses 1 life and you gain 1 life.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Swamp

Pest Summoning

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

Cram Session

You gain 4 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.)

Prosperous Innkeeper

When Prosperous Innkeeper enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever another creature you control enters, you gain 1 life.

Mortality Spear

This spell costs {2} less to cast if you gained life this turn.
Destroy target nonland permanent.

Sedgemoor Witch

Menace
Ward—Pay 3 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 3 life.)
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Pest

When this creature dies, you gain 1 life.

Containment Breach

Destroy target artifact or enchantment. If its mana value is 2 or less, create a 1/1 black and green Pest creature token with "When this creature dies, you gain 1 life."

Dina, Soul Steeper

Whenever you gain life, each opponent loses 1 life.
{1}, Sacrifice another creature: Dina, Soul Steeper gets +X/+0 until end of turn, where X is the sacrificed creature's power.

Mascot Exhibition

Create a 2/1 white and black Inkling creature token with flying, a 3/2 red and white Spirit creature token, and a 4/4 blue and red Elemental creature token.

Forest

Treasure

{T}, Sacrifice this artifact: Add one mana of any color.

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.)