Deathtouch

Whenever Ashnod, Flesh Mechanist attacks, you may sacrifice another creature. If you do, create a tapped Powerstone token.

{5}, Exile a creature card from your graveyard: Create a tapped 3/3 colorless Zombie artifact creature token.

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.

{T}, Sacrifice another black creature: Draw a card.

Zombies you control have flying.

{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Henry Wu, InGen Geneticist and other Human creatures you control have exploit. (When a creature with exploit enters the battlefield, you may sacrifice a creature.)

Whenever a creature you control exploits a non-Human creature, draw a card. If the exploited creature had power 3 or greater, create a Treasure token.

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)

When Invasion of Amonkhet enters the battlefield, each player mills three cards, then each opponent discards a card and you draw a card. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

You may have Lazotep Convert enter the battlefield as a copy of any creature card in a graveyard, except it's a 4/4 black Zombie in addition to its other colors and types.

Whenever Jorn attacks, untap each snow permanent you control.

{T}: You may play target snow permanent card from your graveyard this turn. If you do, it enters the battlefield tapped.

Changeling (This card is every creature type.)

You may have Moritte of the Frost enter the battlefield as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Other snow and Zombie creatures you control get +1/+1.

{S}{S}{S}: Return Narfi, Betrayer King from your graveyard to the battlefield tapped. ({S} can be paid with one mana from a snow source.)

If an opponent gained life this turn, you may pay {B} rather than pay this spell's mana cost.

Target player loses 5 life and you gain 5 life.

You have no maximum hand size.

Sonic Booster -- Whenever Nyssa of Traken attacks, sacrifice X artifacts. When you sacrifice one or more artifacts this way, tap up to X target creatures and you draw X cards.

Doctor's companion (You can have two commanders if the other is the Doctor.)

If an opponent had a green creature enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

{T}, Sacrifice another 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.

When Rona, Disciple of Gix enters the battlefield, you may exile target historic card from your graveyard. (Artifacts, legendaries, and Sagas are historic.)

You may cast spells from among cards exiled with Rona.

{4}, {T}: Exile the top card of your library.

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

{1}{U}, Sacrifice two artifacts: Draw a card.

Artifacts you control are Clues in addition to their other types and have "{2}, Sacrifice this artifact: Draw a card."

Whenever you sacrifice a Clue, target creature can't be blocked this turn.

As The Mimeoplasm enters the battlefield, you may exile two creature cards from graveyards. If you do, it enters the battlefield as a copy of one of those cards with a number of additional +1/+1 counters on it equal to the power of the other card.

At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature.

{1}: Until your next turn, Volrath, the Shapestealer becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.

Deathtouch, lifelink

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.