Rottenmouth Viper

As an additional cost to cast this spell, you may sacrifice any number of nonland permanents. This spell costs {1} less to cast for each permanent sacrificed this way.
Whenever this creature enters or attacks, put a blight counter on it. Then for each blight counter on it, each opponent loses 4 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Grave Sifter

When this creature enters, each player chooses a creature type and returns any number of cards of that type from their graveyard to their hand.

Solitude

Flash
Lifelink
When this creature enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Lumra, Bellow of the Woods

Vigilance, reach
Lumra's power and toughness are each equal to the number of lands you control.
When Lumra enters, mill four cards. Then return all land cards from your graveyard to the battlefield tapped.

Pyre of Heroes

{2}, {T}, Sacrifice a creature: Search your library for a creature card that shares a creature type with the sacrificed creature and has mana value equal to 1 plus that creature's mana value. Put that card onto the battlefield, then shuffle. Activate only as a sorcery.

Patriarch's Bidding

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Temur Battlecrier

During your turn, spells you cast cost {1} less to cast for each creature you control with power 4 or greater.

Up the Beanstalk

When this enchantment enters and whenever you cast a spell with mana value 5 or greater, draw a card.

Animar, Soul of Elements

Protection from white and from black
Whenever you cast a creature spell, put a +1/+1 counter on Animar.
Creature spells you cast cost {1} less to cast for each +1/+1 counter on Animar.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Riveteers Ascendancy

Whenever you sacrifice a creature, you may return target creature card with lesser mana value from your graveyard to the battlefield tapped. Do this only once each turn.

Life Finds a Way

Whenever a nontoken creature you control with power 4 or greater enters, populate. (Create a token that's a copy of a creature token you control.)

Lifeline

Whenever a creature dies, if another creature is on the battlefield, return the first card to the battlefield under its owner's control at the beginning of the next end step.

Cavalier of Dawn

Vigilance
When this creature enters, destroy up to one target nonland permanent. Its controller creates a 3/3 colorless Golem artifact creature token.
When this creature dies, return target artifact or enchantment card from your graveyard to your hand.

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Flamekin Harbinger

When this creature enters, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.