Don't Have

Sidisi, Brood Tyrant

Whenever Sidisi enters or attacks, mill three cards.
Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.

Have

Lotuslight Dancers

Lifelink
When this creature enters, search your library for a black card, a green card, and a blue card. Put those cards into your graveyard, then shuffle.

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.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Meren of Clan Nel Toth

Whenever another creature you control dies, you get an experience counter.
At the beginning of your end step, choose target creature card in your graveyard. If that card's mana value is less than or equal to the number of experience counters you have, return it to the battlefield. Otherwise, put it into your hand.

Yarok, the Desecrated

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

Death Begets Life

Destroy all creatures and enchantments. Draw a card for each permanent destroyed this way.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fangkeeper's Familiar

Flash
When this creature enters, choose one —
• You gain 3 life and surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
• Destroy target enchantment.
• Counter target creature spell.