, : Tap target creature.

Magical Tinkering — , , Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.

: Add .

Channel — , Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs less to activate for each legendary creature you control.

Flying

Whenever Oteclan Levitator attacks, target attacking creature without flying gains flying until end of turn.

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.

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.

Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control with a +1/+1 counter on it.

Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature deals combat damage to a player, return target creature card with mutate from your graveyard to your hand.

This spell costs less to cast if it targets a creature spell.

Counter target spell.

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.

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.)

At the beginning of your upkeep, choose one at random. Create a red and white creature token with those characteristics.

• 3/1 Human Warrior with trample and haste.

• 2/1 Human Cleric with lifelink and haste.

• 1/2 Human Rogue with haste and "When this creature enters the battlefield, it deals 1 damage to any target."

Outnumber deals damage to target creature equal to the number of creatures you control.

Target opponent exiles the top X cards of their library face down. You may look at and play those cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any type to cast it.

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Trample, haste

Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Choose one —

• Destroy target artifact or enchantment.

• Target creature you control explores, then it explores again. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard. Then repeat this process.)

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and Overabundance deals 1 damage to the player.

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Splice onto Arcane (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

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.

Creatures you control get +2/+2 and gain trample until end of turn.

Enchant opponent

When Overencumbered enters the battlefield, enchanted opponent creates a Clue token, a Food token, and a Junk token.

At the beginning of combat on enchanted opponent's turn, that player may pay for each artifact they control. If they don't, creatures can't attack this combat.

Target player draws seven cards.

Enrage — Whenever Overgrown Armasaur is dealt damage, create a 1/1 green Saproling creature token.

Sacrifice a land: You gain 3 life.

When Overgrown Pest enters the battlefield, look at the top five cards of your library. You may reveal a land or double-faced card from among them and put that card into your hand. Put the rest on the bottom of your library in a random order.

Enchant land

Whenever enchanted land is tapped for mana, its controller adds an additional .

As Overlaid Terrain enters the battlefield, sacrifice all lands you control.

Lands you control have ": Add two mana of any one color."

, , Sacrifice Overloaded Mage-Ring: Copy target spell you control. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)

Counter target spell unless its controller pays for each artifact you control.

Creatures you control get +3/+3 and gain trample until end of turn.

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.

At the beginning of your upkeep, if you have four or more creature cards in your graveyard, you may return target creature card from your graveyard to your hand.

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.)

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.)

Creatures you control get +3/+3 until end of turn.

When Overwhelmed Archivist enters the battlefield, draw a card, then discard a card.

Disturb (You may cast this card from your graveyard transformed for its disturb cost.)

Creatures you control gain vigilance and trample until end of turn. Roll a d20.

1–9 | Creatures you control get +2/+2 until end of turn.

10–19 | Put two +1/+1 counters on each creature you control.

20 | Put four +1/+1 counters on each creature you control.

Whenever you attack with three or more creatures, draw a card.

This spell costs less to cast for each creature card in your graveyard.

Exile target creature or planeswalker.

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

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.

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

When Oxidda Scrapmelter enters the battlefield, destroy target artifact.

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead.

, : Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery.

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

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.

Pack Rat's power and toughness are each equal to the number of Rats you control.

, Discard a card: Create a token that's a copy of Pack Rat.