: Prevent all damage that would be dealt to target creature this turn.

Grandeur — Discard another card named Oriss, Samite Guardian: Target player can't cast spells this turn, and creatures that player controls can't attack this turn.

Flying, trample, lifelink

Sacrifice another creature: Draw a card.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever Ornery Dilophosaur attacks, if you control a creature with power 4 or greater, Ornery Dilophosaur gets +2/+2 until end of turn.

When Ornery Kudu enters the battlefield, put a -1/-1 counter on target creature you control.

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

: Add one mana of any color.

: Add one mana of any color.

Whenever Orochi Ranger deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

: Add .

, : Create a token that's a copy of another target creature you control. It gains haste. Sacrifice it at the beginning of the next end step. Activate only as a sorcery.

, : Create five tokens that are copies of another target creature you control. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.

Changeling

Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.

When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Deathtouch

Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

: Target player gains 1 life.

: Each player loses 1 life.

Whenever Orzhov Racketeers deals combat damage to a player, that player discards a card.

Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Vigilance

, Sacrifice an artifact: Target creature you control gets +2/+0 until end of turn.

, , Exile an artifact card with mana value X from your graveyard: Create two tokens that are copies of the exiled card. Activate only as a sorcery.

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.

, : Tap target creature.

Otarian Juggernaut can't be blocked by Walls.

Threshold — As long as seven or more cards are in your graveyard, Otarian Juggernaut gets +3/+0 and attacks each combat if able.

Dinosaur spells you cast cost less to cast.

: Target Dinosaur gains haste until end of turn.

Flash

When Otherworldly Escort dies, if it's not a Spirit, return it to the battlefield under its owner's control with four charge counters on it. It's a Spirit Detective. (It's no longer a Human.)

, , Remove a charge counter from Otherworldly Escort: Destroy target creature that dealt damage to you this turn.

, Sacrifice Ouphe Vandals: Counter target activated ability from an artifact source and destroy that artifact if it's on the battlefield. (Mana abilities can't be targeted.)

When Outcaster Greenblade enters the battlefield, search your library for a basic land card or a Desert card, reveal it, put it into your hand, then shuffle.

Outcaster Greenblade gets +1/+1 for each Desert you control.

Outland Boar can't be blocked by creatures with power 2 or less.

, Sacrifice Outland Liberator: Destroy target artifact or enchantment.

Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

When Outlaw Stitcher enters the battlefield, create a 2/2 blue and black Zombie Rogue creature token, then put two +1/+1 counters on that token for each spell you've cast this turn other than the first.

Plot (You may pay and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

: The next 1 damage that would be dealt to Outrider en-Kor this turn is dealt to target creature you control instead.

Whenever an artifact enters the battlefield under your control, you may return Ovalchase Daredevil from your graveyard to your hand.

Flash

Flying

Exploit (When this creature enters the battlefield, you may sacrifice a creature.)

When Overcharged Amalgam exploits a creature, counter target spell, activated ability, or triggered ability.

Defender

: You gain 1 life.

, Sacrifice Overgrown Arch: Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Defender

: Add for each creature you control with defender.

When Overgrowth Elemental enters the battlefield, put a +1/+1 counter on another target Elemental you control.

Whenever another creature you control dies, you gain 1 life. If that creature was an Elemental, put a +1/+1 counter on Overgrowth Elemental.

First Contact — Whenever Overseer of Vault 76 or another creature with power 3 or less enters the battlefield under your control, put a quest counter on Overseer of Vault 76.

At the beginning of combat on your turn, you may remove three quest counters from among permanents you control. When you do, put a +1/+1 counter on each creature you control and they gain vigilance until end of turn.

Menace

Whenever Overt Operative deals combat damage to a player, it assembles a Contraption. (Put the top card of your Contraption deck face up onto one of your sprockets.)

When Overwhelmed Apprentice enters the battlefield, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

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.)

When Ovinomancer enters the battlefield, sacrifice it unless you return three basic lands you control to their owner's hand.

, Return Ovinomancer to its owner's hand: Destroy target creature. It can't be regenerated. That creature's controller creates a 0/1 green Sheep creature token.

Partner with Blue, Loyal Raptor

: Put your choice of a menace, trample, reach, or haste counter on target Dinosaur. Activate only as a sorcery.

Trample

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

At the beginning of your end step, if creatures you control have total power 8 or greater, draw a card.

Vigilance

Ox Drover can't be blocked by Oxen.

Whenever Ox Drover enters the battlefield or attacks, target opponent creates a 2/4 white Ox creature token and you draw a card.

Sacrifice an artifact: Oxidda Daredevil gains haste until end of turn.

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

Haste

Oyaminartok, Polar Werebear has hexproof if it hasn't dealt damage yet.

Whenever Oyaminartok deals combat damage to a player, create a Food token.

, Sacrifice a Food: Draft a card from Oyaminartok's spellbook. When you do, add . Spend this mana only to cast blue creature spells.

Flash (You may cast this spell any time you could cast an instant.)

When Pack Guardian enters the battlefield, you may discard a land card. If you do, create a 2/2 green Wolf creature token.

: Each creature you control named Pack Mastiff gets +1/+0 until end of turn.

At the beginning of combat on your turn, if you control another Wolf or Werewolf, put a +1/+1 counter on Packsong Pup.

When Packsong Pup dies, you gain life equal to its power.

Menace

Whenever a player casts their first spell each turn, they create a Treasure token.

Whenever an artifact an opponent controls is put into a graveyard from the battlefield, Pain Distributor deals 1 damage to that player.

Inspired — Whenever Pain Seer becomes untapped, reveal the top card of your library and put that card into your hand. You lose life equal to that card's mana value.

At the beginning of your upkeep, roll a six-sided die. Painiac gets +X/+0 until end of turn, where X is the result.

As Painter's Servant enters the battlefield, choose a color.

All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.