mtg.wtf

Flying
Ward {2}
Whenever Obsessive Collector deals combat damage to a player, seek a card with mana value equal to the number of cards in your hand.

Draw a card.
Madness {U}

When Obsessive Skinner enters the battlefield, put a +1/+1 counter on target creature.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, put a +1/+1 counter on target creature.

{T}: Draw a card, then discard a card.
{2}{U}{B}, {T}, Sacrifice Obsessive Stitcher: Return target creature card from your graveyard to the battlefield.

Protection from black
{W}: Target creature gains protection from black until end of turn.

Equipped creature gets +2/+1 and has haste.
Whenever a Warrior creature enters the battlefield, you may attach Obsidian Battle-Axe to it.
Equip {3}

This spell costs {1} less to cast for each land your opponents control that could produce {C}.
Flying
When Obsidian Charmaw enters the battlefield, destroy target nonbasic land an opponent controls.

{1}{R}{R}: Put a blaze counter on target land without a blaze counter on it. For as long as that land has a blaze counter on it, it has "At the beginning of your upkeep, this land deals 1 damage to you."

Obsidian Obelisk enters the battlefield tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

When Obstinate Baloth enters the battlefield, you gain 4 life.
If a spell or ability an opponent controls causes you to discard Obstinate Baloth, put it onto the battlefield instead of putting it into your graveyard.

If you would draw a card, you may skip that draw instead.

At the beginning of combat on your turn, up to one target land you control becomes an X/X Elemental creature with trample and haste until end of turn, where X is Obuun's power. It's still a land.
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on target creature.

Flying

Flash
Flying
Whenever another Faerie enters the battlefield under your control, each opponent loses 1 life.

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.

Draw X cards, then discard X cards. Create a 1/1 white Spirit creature token with flying for each card type among cards discarded this way.

Flying
When Oceanus Dragon enters the battlefield, tap target creature an opponent controls. Goad it.

Trample
Ochre Jelly enters the battlefield with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters the battlefield with half that many +1/+1 counters on it, rounded down.

Trample
Ward {2}
Ochre Jelly enters the battlefield with X +1/+1 counters on it.
Split — When Ochre Jelly dies, if it had two or more +1/+1 counters on it, create a token that's a copy of it at the beginning of the next end step. The token enters the battlefield with half that many +1/+1 counters on it, rounded down.

This spell costs {8} less to cast if you have eight or more instant and/or sorcery cards in your graveyard.
Ward {8}
Magecraft — Whenever you cast or copy an instant or sorcery spell, target creature has base power and toughness 8/8 until end of turn.

When Octo Opus enters the battlefield, create a 4/4 blue Octopus Performer creature token named Contortionist with "At the beginning of your upkeep, you may fold this token in half." (It becomes 2/2, then 1/1, ½/½, and so on.)
Sacrifice Octo Opus: Draw a card and an additional card for each of Contortionist's folds.

When Octoprophet enters the battlefield, scry 2.

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Totem armor