When Nurturing Bristleback enters the battlefield, create a 3/3 green Dinosaur creature token.

Forestcycling (, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Whenever you gain life, you may put that many +1/+1 counters on each creature you control. Do this only once each turn.

Trample

Other creatures you control have trample.

Trample

If you tap a permanent for mana, it produces three times as much of that mana instead.

Put two +1/+1 counters on target creature. (Then exile this card. You may cast the creature later from exile.)

Vigilance

Other creatures you control get +0/+2 and have vigilance.

Flying, trample

Whenever an opponent searches their library, that player sacrifices a creature and loses 10 life.

Whenever another creature dies, put a +1/+1 counter on Ob Nixilis, Unshackled.

Companion — Your starting deck contains only cards with odd mana values 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.)

If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

This spell costs less to cast for each land your opponents control that could produce .

Flying

When Obsidian Charmaw enters the battlefield, destroy target nonbasic land an opponent controls.

Flying

Flying

When Oceanus Dragon enters the battlefield, tap target creature an opponent controls. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Disguise (You may cast this card face down for as a 2/2 creature with ward . Turn it face up any time for its disguise cost.)

When Offender at Large enters the battlefield or is turned face up, up to one target creature gets +2/+0 until end of turn.

When Ogre Arsonist enters the battlefield, destroy target land.

Menace

Whenever Ogre Chitterlord enters the battlefield or attacks, create two 1/1 black Rat creature tokens with "This creature can't block." Then if you control five or more Rats, each Rat you control gets +2/+0 until end of turn.

Whenever Ogre Geargrabber attacks, gain control of target Equipment an opponent controls until end of turn. Attach it to Ogre Geargrabber. When you lose control of that Equipment, unattach it.

When Ogre Savant enters the battlefield, if was spent to cast it, return target creature to its owner's hand.

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.

Rats you control have deathtouch.

When Oil-Gorger Troll enters the battlefield, you gain 3 life. Then if you control a permanent with an oil counter on it, draw a card.

Vigilance

If one or more creature tokens would be created under your control, three times that many of those tokens are created instead.

When Ojer Taq dies, return it to the battlefield tapped and transformed under its owner's control.

Flying, trample

Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

Flying

Cycling (, Discard this card: Draw a card.)

Embalm (, Exile this card from your graveyard: Create a token that's a copy of it, except it's a white Zombie Bird Soldier with no mana cost. Embalm only as a sorcery.)

As long as you have more cards in hand than each opponent, Okina Nightwatch gets +3/+3.

Trample

Other creatures you control have trample.

When Old One Eye enters the battlefield, create a 5/5 green Tyranid creature token.

Fast Healing — At the beginning of your precombat main phase, you may discard two cards. If you do, return Old One Eye from your graveyard to your hand.

Trample

Whenever Oliphaunt attacks, another target creature you control gets +2/+0 and gains trample until end of turn.

Mountaincycling (, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Menace

Whenever Olivia's Attendants deals damage, create that many Blood tokens. (They're artifacts with ", , Discard a card, Sacrifice this artifact: Draw a card.")

: Olivia's Attendants deals 1 damage to any target.

When Oltec Archaeologists enters the battlefield, choose one —

• Return target artifact card from your graveyard to your hand.

• Scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

If you would lose unspent mana, that mana becomes black instead.

At the beginning of your precombat main phase, look at the top card of your library. You may reveal that card if it has three or more colored mana symbols in its mana cost. If you do, add three mana in any combination of its colors and put it into your hand. If you don't reveal it, put it into your hand.

Affinity for Clowns (This spell costs less to cast for each Clown you control.)

Trample

Reach

: Onakke Javelineer deals 2 damage to target player or battle.

Haste

At the beginning of your upkeep, return a red creature you control to its owner's hand.

More Than Meets the Eye (You may cast this card converted for .)

At the beginning of each end step, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

When Optimus Prime dies, return it to the battlefield converted under its owner's control.

Trample

Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

Trample

Whenever another creature dies, put a +1/+1 counter on Orca, Siege Demon.

When Orca dies, it deals damage equal to its power divided as you choose among any number of targets.

When Orchard Strider enters the battlefield, create two Food tokens. (They're artifacts with ", , Sacrifice this artifact: You gain 3 life.")

Basic landcycling (, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Whenever Orcish Squatters attacks and isn't blocked, you may gain control of target land defending player controls for as long as you control Orcish Squatters. If you do, Orcish Squatters assigns no combat damage this turn.

Whenever you cast a Spirit or Arcane spell, you may destroy target nonbasic land.

Trample

Orgg can't attack if defending player controls an untapped creature with power 3 or greater.

Orgg can't block creatures with power 3 or greater.

Flying

Tribute 2 (As this creature enters the battlefield, an opponent of your choice may put two +1/+1 counters on it.)

When Ornitharch enters the battlefield, if tribute wasn't paid, create two 1/1 white Bird creature tokens with flying.

Flying

Whenever Oros, the Avenger deals combat damage to a player, you may pay . If you do, Oros deals 3 damage to each nonwhite creature.

This spell costs less to cast for each different mana value among cards in your graveyard.

Whenever you discard a nonland card, you may cast it from your graveyard.

Flying, lifelink, haste

Whenever Otharri, Suns' Glory attacks, you get an experience counter. Then create a 2/2 red Rebel creature token that's tapped and attacking for each experience counter you have.

, Tap an untapped Rebel you control: Return Otharri from your graveyard to the battlefield tapped.

Renown 6 (When this creature deals combat damage to a player, if it isn't renowned, put six +1/+1 counters on it and it becomes renowned.)

Outland Colossus can't be blocked by more than one creature.

Overbeing of Myth's power and toughness are each equal to the number of cards in your hand.

At the beginning of your draw step, draw an additional card.

Flying

When Overseer of the Damned enters the battlefield, you may destroy target creature.

Whenever a nontoken creature an opponent controls dies, create a tapped 2/2 black Zombie creature token.

Whenever you commit a crime during your turn, Overzealous Muscle gains indestructible until end of turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime. Damage and effects that say "destroy" don't destroy a creature with indestructible.)

Trample

Keen Senses — When Owlbear enters the battlefield, draw a card.

When Ox of Agonas enters the battlefield, discard your hand, then draw three cards.

Escape—, Exile eight other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Ox of Agonas escapes with a +1/+1 counter on it.

Affinity for Mountains (This spell costs less to cast for each Mountain you control.)

Haste