Phyrexian Dreadnought

Trample
When Phyrexian Dreadnought enters the battlefield, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Gigantoplasm

You may have Gigantoplasm enter the battlefield as a copy of any creature on the battlefield, except it has "{X}: This creature has base power and toughness X/X."

Phantasmal Image

You may have Phantasmal Image enter the battlefield as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Hapless Researcher

Sacrifice Hapless Researcher: Draw a card, then discard a card.

Brenard, Ginger Sculptor

Each creature you control that's a Food or a Golem gets +2/+2 and has trample.
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's a 1/1 Food Golem artifact creature in addition to its other types and it has "{2}, {T}, Sacrifice this artifact: You gain 3 life."

Riftsweeper

When Riftsweeper enters the battlefield, choose target face-up exiled card. Its owner shuffles it into their library.

Eternal Scourge

You may cast Eternal Scourge from exile.
When Eternal Scourge becomes the target of a spell or ability an opponent controls, exile Eternal Scourge.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Karmic Guide enters the battlefield, return target creature card from your graveyard to the battlefield.

Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Birthing Pod

({G/P} can be paid with either {G} or 2 life.)
{1}{G/P}, {T}, Sacrifice a creature: Search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put that card onto the battlefield, then shuffle. Activate only as a sorcery.

Ashnod's Altar

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Arena Rector

When Arena Rector dies, you may exile it. If you do, search your library for a planeswalker card, put it onto the battlefield, then shuffle.

Food Chain

Exile a creature you control: Add X mana of any one color, where X is 1 plus the exiled creature's mana value. Spend this mana only to cast creature spells.

Concordant Crossroads

Loyal Retainers

Sacrifice Loyal Retainers: Return target legendary creature card from your graveyard to the battlefield. Activate only during your turn, before attackers are declared.

Saffi Eriksdotter

Sacrifice Saffi Eriksdotter: When target creature is put into your graveyard this turn, return that card to the battlefield.

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Body Double

You may have Body Double enter the battlefield as a copy of any creature card in a graveyard.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Reveillark

Flying
When Reveillark leaves the battlefield, return up to two target creature cards with power 2 or less from your graveyard to the battlefield.
Evoke {5}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Sidisi's Faithful

Exploit (When this creature enters the battlefield, you may sacrifice a creature.)
When Sidisi's Faithful exploits a creature, return target creature to its owner's hand.

Academy Rector

When Academy Rector dies, you may exile it. If you do, search your library for an enchantment card, put that card onto the battlefield, then shuffle.