Species Specialist

As Species Specialist enters, choose a creature type.
Whenever a creature of the chosen type dies, you may draw a card.

Saskia the Unyielding

Vigilance, haste
As Saskia the Unyielding enters, choose a player.
Whenever a creature you control deals combat damage to a player, it deals that much damage to the chosen player.

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Kynaios and Tiro of Meletis

At the beginning of your end step, draw a card. Each player may put a land card from their hand onto the battlefield, then each opponent who didn't draws a card.

Teysa, Envoy of Ghosts

Vigilance, protection from creatures
Whenever a creature deals combat damage to you, destroy that creature. Create a 1/1 white and black Spirit creature token with flying.

Chainer, Nightmare Adept

Discard a card: You may cast a creature spell from your graveyard this turn. Activate only once each turn.
Whenever a nontoken creature you control enters, if you didn't cast it from your hand, it gains haste until your next turn.

Jhoira, Weatherlight Captain

Whenever you cast a historic spell, draw a card. (Artifacts, legendaries, and Sagas are historic.)

Niambi, Esteemed Speaker

Flash
When Niambi, Esteemed Speaker enters, you may return another target creature you control to its owner's hand. If you do, you gain life equal to that creature's mana value.
{1}{W}{U}, {T}, Discard a legendary card: Draw two cards.

Saffi Eriksdotter

Sacrifice Saffi Eriksdotter: When target creature is put into your graveyard this turn, return that card to the battlefield.

Heron's Grace Champion

Flash
Lifelink
When Heron's Grace Champion enters, other Humans you control get +1/+1 and gain lifelink until end of turn.

Leinore, Autumn Sovereign

Coven — At the beginning of combat on your turn, put a +1/+1 counter on up to one target creature you control. Then if you control three or more creatures with different powers, draw a card.

Thalia's Lieutenant

When Thalia's Lieutenant enters, put a +1/+1 counter on each other Human you control.
Whenever another Human you control enters, put a +1/+1 counter on Thalia's Lieutenant.

Jodah, Archmage Eternal

Flying
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Champion of the Parish

Whenever another Human enters under your control, put a +1/+1 counter on Champion of the Parish.

Hero of Precinct One

Whenever you cast a multicolored spell, create a 1/1 white Human creature token.

Thalia's Lancers

First strike
When Thalia's Lancers enters, you may search your library for a legendary card, reveal it, put it into your hand, then shuffle.

Atris, Oracle of Half-Truths

Menace
When Atris, Oracle of Half-Truths enters, target opponent looks at the top three cards of your library and separates them into a face-down pile and a face-up pile. Put one pile into your hand and the other into your graveyard.

Adriana, Captain of the Guard

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other creatures you control have melee. (If a creature has multiple instances of melee, each triggers separately.)

General Ferrous Rokiric

Hexproof from monocolored
Whenever you cast a multicolored spell, create a 4/4 red and white Golem artifact creature token.

Chulane, Teller of Tales

Vigilance
Whenever you cast a creature spell, draw a card, then you may put a land card from your hand onto the battlefield.
{3}, {T}: Return target creature you control to its owner's hand.

Hostage Taker

When Hostage Taker enters, exile another target creature or artifact until Hostage Taker leaves the battlefield. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Reki, the History of Kamigawa

Whenever you cast a legendary spell, draw a card.

Ravos, Soultender

Flying
Other creatures you control get +1/+1.
At the beginning of your upkeep, you may return target creature card from your graveyard to your hand.
Partner (You can have two commanders if both have partner.)

Blade Historian

Attacking creatures you control have double strike.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Tymna the Weaver

Lifelink
At the beginning of each of your postcombat main phases, you may pay X life, where X is the number of opponents that were dealt combat damage this turn. If you do, draw X cards.
Partner (You can have two commanders if both have partner.)

Judith, the Scourge Diva

Other creatures you control get +1/+0.
Whenever a nontoken creature you control dies, Judith, the Scourge Diva deals 1 damage to any target.

Riders of Gavony

Vigilance
As Riders of Gavony enters, choose a creature type.
Human creatures you control have protection from creatures of the chosen type.

Wulfgar of Icewind Dale

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
If a creature you control attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

General Kudro of Drannith

Other Humans you control get +1/+1.
Whenever General Kudro of Drannith or another Human you control enters, exile target card from an opponent's graveyard.
{2}, Sacrifice two Humans: Destroy target creature with power 4 or greater.

Knight of New Alara

Each other multicolored creature you control gets +1/+1 for each of its colors.

Surrak Dragonclaw

Flash
This spell can't be countered.
Creature spells you control can't be countered.
Other creatures you control have trample.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Jirina Kudro

When Jirina Kudro enters, create a 1/1 white Human Soldier creature token for each time you've cast a commander from the command zone this game.
Other Humans you control get +2/+0.

Anafenza, the Foremost

Whenever Anafenza, the Foremost attacks, put a +1/+1 counter on another target tapped creature you control.
If a nontoken creature an opponent owns would die or a creature card not on the battlefield would be put into an opponent's graveyard, exile that card instead.

Katilda, Dawnhart Prime

Protection from Werewolves
Human creatures you control have "{T}: Add one mana of any of this creature's colors."
{4}{G}{W}, {T}: Put a +1/+1 counter on each creature you control.