Flash
When Blind Keelah enters the battlefield and whenever you cast a spell during an opponent's turn, each opponent loses 1 life and you surveil 1. This ability triggers only once each turn.

Flying, haste
When Blistering Cryophoenix enters the battlefield, discard any number of cards, then draw that many cards.
If a spell you own which had its flashback cost paid would be put into exile, put it into your hand instead.

Flying, trample
When Blooming Cocollona enters the battlefield, you may have it deal 3 damage to another target creature or planeswalker. If you do, that permanent's controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

When Brass Baker enters the battlefield, create a Food token.

Flying
When Breaching Jaxl enters the battlefield, untap target nonland permanent.
Wander {2}{U}

Flying
When Bringer of Heliod's Light enters the battlefield, you may bless target creature.

When Bulvem Wardcleanser enters the battlefield, you may destroy target artifact or enchantment.

Drop — When Bumping Betta enters the battlefield, if you didn't cast any creature spells during your last turn, return up to one target nonland permanent to its owner's hand.

When Burning Wisdom enters the battlefield, exile the top card of your library. You may play it until end of turn.
Whenever a source you control deals noncombat damage to an opponent, exile Burning Wisdom. You may play it during your next turn.

When Cairnblade of the Ancients enters the battlefield, destroy target creature an opponent controls.
Equipped creature gets +4/+2 and has vigilance.
Equip {4}

When Caller of Ferocity enters the battlefield, bless target creature.

Flash
Enchant creature
When Capture Sphere enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

When Carving Instructor enters the battlefield, put a flying counter on target creature you control.

Trample
When Centaur Mentor enters the battlefield, target creature gets +X/+0 until end of turn, where X is your devotion to green.

First strike
When Chosen of Heliod enters the battlefield, bless target creature.
{4}{W}{W}: Bless target creature you control. Activate only as a sorcery.

When Chromatic Hart enters the battlefield, you may exile target card from a graveyard.
{T}: Add one mana of any color.

When Cliffwalker enters the battlefield, return a permanent you control to its owner's hand.
Wander {1}{W}

Drop — When Club Promoter enters the battlefield, choose one. If you didn't cast any creature spells during your last turn, you may choose both instead.
• Destroy target artifact or enchantment.
• Put two +1/+1 counters on Club Promoter.

Flash
When Conduit of Change enters the battlefield, if you cast it, return all other nonland permanents to their owner's hands.
Spellcharge 7

Indulgence
When Conspiracy of Wealth enters the battlefield, draw a card.
Whenever you indulge, you may exile target card from a graveyard.

Deathtouch
When Corpse Thieves enters the battlefield, mill three cards.
Corpse Thieves's power is equal to the greatest mana value among cards in your graveyard.

Flash
When Corrosive Spitter enters the battlefield, destroy all creatures that were dealt damage this turn.

When Courtless Spiritcaller enters the battlefield, create a 1/1 white Spirit creature token with flying.
{4}{W}, Sacrifice Courtless Spiritcaller: Create two 1/1 white Spirit creature tokens with flying.

When Crownguard Instructor enters the battlefield, put a vigilance counter on target creature you control.

Flash
Haste
When Cuernas, Victor of the Ring enters the battlefield, it and other legendary creatures you control gain trample and indestructible until end of turn.