Oona, Queen of the Fae
Casting Cost:
Flying
: Choose a color. Target opponent exiles the top X cards of his or her library. For each card of the chosen color exiled this way, put a 1/1 blue and black Faerie Rogue creature token with flying onto the battlefield.
$ 000
Oona's Prowler
Discard a card: Oona's Prowler gets -2/-0 until end of turn. Any player may activate this ability.
One With Nothing
Discard your hand.
Omniscience
You may cast nonland cards from your hand without paying their mana costs.
Omnath, Locus of Rage
Landfall — Whenever a land enters the battlefield under your control, put a 5/5 red and green Elemental creature token onto the battlefield.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to target creature or player.
Omnath, Locus of Mana
Green mana doesn't empty from your mana pool as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each green mana in your mana pool.
Olivia Voldaren
: Olivia Voldaren deals 1 damage to another target creature. That creature becomes a Vampire in addition to its other types. Put a +1/+1 counter on Olivia Voldaren.
: Gain control of target Vampire for as long as you control Olivia Voldaren.
Old Man of the Sea
You may choose not to untap Old Man of the Sea during your untap step.
: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.
Old Fogey
Phasing, cumulative upkeep , echo, fading 3, bands with other Dinosaurs, protection from Homarids, snow-covered plainswalk, flanking, rampage 2
Okina, Temple to the Grandfathers
: Add to your mana pool.
, : Target legendary creature gets +1/+1 until end of turn.
Oketra the True
Double strike, indestructible
Oketra the True can't attack or block unless you control at least three other creatures.
: Create a 1/1 white Warrior creature token with vigilance.
Ohran Viper
Whenever Ohran Viper deals combat damage to a creature, destroy that creature at the end of combat.
Whenever Ohran Viper deals combat damage to a player, you may draw a card.
Obzedat, Ghost Council
When Obzedat, Ghost Council enters the battlefield, target opponent loses 2 life and you gain 2 life.
At the beginning of your end step, you may exile Obzedat. If you do, return it to the battlefield under its owner's control at the beginning of your next upkeep. It gains haste.