Arahbo, the First Fang

Other Cats you control get +1/+1.
Whenever Arahbo or another nontoken Cat you control enters, create a 1/1 white Cat creature token.

Skyship Buccaneer

Flying
Raid — When this creature enters, if you attacked this turn, draw a card.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Hinterland Sanctifier

Whenever another creature you control enters, you gain 1 life.

Charming Prince

When this creature enters, choose one —
• Scry 2.
• You gain 3 life.
• Exile another target creature you own. Return it to the battlefield under your control at the beginning of the next end step.

Kykar, Zephyr Awakener

Flying
Whenever you cast a noncreature spell, choose one —
• Exile another target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.
• Create a 1/1 white Spirit creature token with flying.

Bigfin Bouncer

When this creature enters, return target creature an opponent controls to its owner's hand.

Campus Guide

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

Sun-Blessed Healer

Kicker {1}{W} (You may pay an additional {1}{W} as you cast this spell.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, if it was kicked, return target nonland permanent card with mana value 2 or less from your graveyard to the battlefield.

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Guarded Heir

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, create two 3/3 white Knight creature tokens.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Felidar Savior

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When this creature enters, put a +1/+1 counter on each of up to two other target creatures you control.

Exclusion Mage

Lightshell Duo

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Storm Fleet Spy

Raid — When this creature enters, if you attacked this turn, draw a card.

Mischievous Pup

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, return up to one other target permanent you control to its owner's hand.

Harbinger of the Tides

You may cast this spell as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When this creature enters, you may return target tapped creature an opponent controls to its owner's hand.

Micromancer

When this creature enters, you may search your library for an instant or sorcery card with mana value 1, reveal it, put it into your hand, then shuffle.

Banishing Light

When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Skyknight Squire

Whenever another creature you control enters, put a +1/+1 counter on this creature.
As long as this creature has three or more +1/+1 counters on it, it has flying and is a Knight in addition to its other types.

Prideful Parent

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature enters, create a 1/1 white Cat creature token.

Resolute Reinforcements

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, create a 1/1 white Soldier creature token.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Disenchant

Aetherize

Return all attacking creatures to their owner's hand.

Burrog Befuddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, target creature an opponent controls gets -1/-0 until end of turn.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Helpful Hunter

Cloudblazer

Flying
When this creature enters, you gain 2 life and draw two cards.

Icewind Elemental

Flying
When this creature enters, draw a card, then discard a card.

Youthful Valkyrie

Flying
Whenever another Angel you control enters, put a +1/+1 counter on this creature.

Corsair Captain

When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Other Pirates you control get +1/+1.

Regal Caracal

Other Cats you control get +1/+1 and have lifelink. (Damage dealt by those creatures also causes you to gain that much life.)
When this creature enters, create two 1/1 white Cat creature tokens with lifelink.