Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is this creature's power.

Bennie Bracks, Zoologist

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of each end step, if you created a token this turn, draw a card.

Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Thalia's Lieutenant

When this creature enters, put a +1/+1 counter on each other Human you control.
Whenever another Human you control enters, put a +1/+1 counter on this creature.

Coppercoat Vanguard

Each other Human you control gets +1/+0 and has ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Hero of Bladehold

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Whenever this creature attacks, create two 1/1 white Soldier creature tokens that are tapped and attacking.

Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Mace of the Valiant

Equipped creature gets +1/+1 for each charge counter on this Equipment and has vigilance. (Attacking doesn't cause it to tap.)
Whenever a creature you control enters, put a charge counter on this Equipment.
Equip {3}

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Court Street Denizen

Whenever another white creature you control enters, tap target creature an opponent controls.

Goldnight Commander

Whenever another creature you control enters, creatures you control get +1/+1 until end of turn.

Pearl Medallion

White spells you cast cost {1} less to cast.

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Sol Ring

Champion of the Parish

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

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Adeline, Resplendent Cathar

Vigilance
Adeline's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Rabble Rousing

Hideaway 5 (When this enchantment enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Whenever you attack with one or more creatures, create that many 1/1 green and white Citizen creature tokens. Then if you control ten or more creatures, you may play the exiled card without paying its mana cost.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Light from Within

Chroma — Each creature you control gets +1/+1 for each white mana symbol in its mana cost.