Mercurial Transformation

Until end of turn, target nonland permanent loses all abilities and becomes your choice of a blue Frog creature with base power and toughness 1/1 or a blue Octopus creature with base power and toughness 4/4.

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.)

Teachings of the Archaics

If an opponent has more cards in hand than you, draw two cards. Draw three cards instead if an opponent has at least four more cards in hand than you.

Necrotic Fumes

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

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Fractal Summoning

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it.

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Pest Summoning

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

Introduction to Annihilation

Exile target nonland permanent. Its controller draws a card.

Introduction to Prophecy

Fading Hope

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Confront the Past

Choose one —
• Return target planeswalker card with mana value X or less from your graveyard to the battlefield.
• Remove twice X loyalty counters from target planeswalker an opponent controls.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Inkling Summoning

Create a 2/1 white and black Inkling creature token with flying.

Eyetwitch

Flying
When Eyetwitch dies, 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.)

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Environmental Sciences

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

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Island

Divide by Zero

Return target spell or permanent with mana value 1 or greater to its owner's hand.
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.)

Infernal Grasp

Destroy target creature. You lose 2 life.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

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.

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."

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.