Sidisi's Faithful

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

Sidisi, Undead Vizier

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When Sidisi exploits a creature, you may search your library for a card, put it into your hand, then shuffle.

Fell Stinger

Deathtouch
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target player draws two cards and loses 2 life.

Stitched Assistant

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, scry 1, then draw a card. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)

Silumgar Sorcerer

Flash (You may cast this spell any time you could cast an instant.)
Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When Silumgar Sorcerer exploits a creature, counter target creature spell.

Skull Skaab

Exploit (When this creature enters, you may sacrifice a creature.)
Whenever a creature you control exploits a nontoken creature, create a 2/2 black Zombie creature token.

Qarsi Sadist

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, target opponent loses 2 life and you gain 2 life.

Henry Wu, InGen Geneticist

Henry Wu and other Human creatures you control have exploit. (When a creature with exploit enters, 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.

Overcharged Amalgam

Flash
Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, counter target spell, activated ability, or triggered ability.

Vulturous Aven

Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, you draw two cards and you lose 2 life.

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent sacrifices a creature of their choice.

Minister of Pain

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, creatures your opponents control get -1/-1 until end of turn.

Profaner of the Dead

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, return to their owners' hands all creatures your opponents control with toughness less than the exploited creature's toughness.