Izoni, Center of the Web

Legendary Creature — Elf Detective (5/4)

Menace
Whenever Izoni, Center of the Web enters the battlefield or attacks, you may collect evidence 4. If you do, create two 2/1 black and green Spider creature tokens with menace and reach.
Sacrifice four tokens: Surveil 2, then draw two cards. You gain 2 life.

Izoni, Thousand-Eyed

Legendary Creature — Elf Shaman (2/3)

Undergrowth — When Izoni, Thousand-Eyed enters the battlefield, create a 1/1 black and green Insect creature token for each creature card in your graveyard.
, Sacrifice another creature: You gain 1 life and draw a card.

Izzet Chronarch

Creature — Human Wizard (2/2)

When Izzet Chronarch enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Jasmine Boreal

Legendary Creature — Human (4/5)

Jor Kadeen, the Prevailer

Legendary Creature — Human Warrior (5/4)

First strike
Metalcraft — Creatures you control get +3/+0 as long as you control three or more artifacts.

Joyful Stormsculptor

Creature — Human Shaman (2/3)

When Joyful Stormsculptor enters the battlefield, create two 1/1 blue and red Elemental creature tokens.
Whenever you cast a spell that has convoke, Joyful Stormsculptor deals 1 damage to each opponent and each battle they protect.

Judith, Carnage Connoisseur

Legendary Creature — Human Shaman (3/4)

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this creature dies, it deals 2 damage to each opponent."

Judoon Enforcers

Creature — Alien Rhino Soldier (8/8)

Trample
No more than one creature can attack you each combat.
Suspend 6— (Rather than cast this card from your hand, you may pay and exile it with six time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Juniper Order Ranger

Creature — Human Knight Ranger (2/4)

Whenever another creature enters the battlefield under your control, put a +1/+1 counter on that creature and a +1/+1 counter on Juniper Order Ranger.

Kaervek the Merciless

Legendary Creature — Human Shaman (5/4)

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

Karametra, God of Harvests

Legendary Enchantment Creature — God (6/7)

Indestructible
As long as your devotion to green and white is less than seven, Karametra isn't a creature.
Whenever you cast a creature spell, you may search your library for a Forest or Plains card, put it onto the battlefield tapped, then shuffle.

Karazikar, the Eye Tyrant

Legendary Creature — Beholder (5/5)

Whenever you attack a player, tap target creature that player controls and goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever an opponent attacks another one of your opponents, you and the attacking player each draw a card and lose 1 life.

Kasla, the Broken Halo

Legendary Creature — Angel Ally (5/4)

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature's color.)
Flying, vigilance, haste
Whenever you cast another spell that has convoke, scry 2, then draw a card.

Kathril, Aspect Warper

Legendary Creature — Nightmare Insect (3/3)

When Kathril, Aspect Warper enters the battlefield, put a flying counter on any creature you control if a creature card in your graveyard has flying. Repeat this process for first strike, double strike, deathtouch, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance. Then put a +1/+1 counter on Kathril for each counter put on a creature this way.

Keranos, God of Storms

Legendary Enchantment Creature — God (6/5)

Indestructible
As long as your devotion to blue and red is less than seven, Keranos isn't a creature.
Reveal the first card you draw on each of your turns. Whenever you reveal a land card this way, draw a card. Whenever you reveal a nonland card this way, Keranos deals 3 damage to any target.

Keruga, the Macrosage

Legendary Creature — Dinosaur Hippo (5/4)

Companion — Your starting deck contains only cards with mana value 3 or greater and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.)
When Keruga, the Macrosage enters the battlefield, draw a card for each other permanent you control with mana value 3 or greater.

Kheru Lich Lord

Creature — Zombie Wizard (4/4)

At the beginning of your upkeep, you may pay . If you do, return a creature card at random from your graveyard to the battlefield. It gains flying, trample, and haste. Exile that card at the beginning of your next end step. If it would leave the battlefield, exile it instead of putting it anywhere else.

Kiora, Sovereign of the Deep

Legendary Creature — Merfolk Noble (4/5)

Vigilance, ward
Whenever you cast a Kraken, Leviathan, Octopus, or Serpent spell from your hand, look at the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value less than X from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Kjeldoran Frostbeast

Creature — Elemental Beast (2/4)

At end of combat, destroy all creatures blocking or blocked by Kjeldoran Frostbeast.

Kolaghan, the Storm's Fury

Legendary Creature — Dragon (4/5)

Flying
Whenever a Dragon you control attacks, creatures you control get +1/+0 until end of turn.
Dash (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)