Bovine Intervention

Destroy target artifact or creature. Its controller creates a 2/2 white Ox creature token.

Yoked Ox

Transmogrifying Wand

This artifact enters with three charge counters on it.
{1}, {T}, Remove a charge counter from this artifact: Destroy target creature. Its controller creates a 2/4 white Ox creature token. Activate only as a sorcery.

Earth-Origin Yak

When this creature enters, creatures you control get +1/+1 until end of turn.

Purphoros's Emissary

Bestow {6}{R} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Menace (This creature can't be blocked except by two or more creatures.)
Enchanted creature gets +3/+3 and has menace.

Makindi Ox

Landfall — Whenever a land you control enters, tap target creature an opponent controls.

Liberated Livestock

When this creature dies, create a 1/1 white Cat creature token with lifelink, a 1/1 white Bird creature token with flying, and a 2/4 white Ox creature token. For each of those tokens, you may put an Aura card from your hand and/or graveyard onto the battlefield attached to it.

Holy Cow

Flash
Flying
When this creature enters, you gain 2 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Giant Ox

This creature crews Vehicles using its toughness rather than its power.

Arc Runner

Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Bruse Tarl, Roving Rancher

Oxen you control have double strike.
Whenever Bruse Tarl enters or attacks, exile the top card of your library. If it's a land card, create a 2/2 white Ox creature token. Otherwise, you may cast it until the end of your next turn.

Ox Drover

Vigilance
This creature can't be blocked by Oxen.
Whenever this creature enters or attacks, target opponent creates a 2/4 white Ox creature token and you draw a card.

Pillarfield Ox

Raging Bull

Ox of Agonas

When this creature enters, discard your hand, then draw three cards.
Escape—{R}{R}, Exile eight other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
This creature escapes with a +1/+1 counter on it.

Bartered Cow

When this creature dies and when you discard this card, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Inquisitor's Ox

Delirium — This creature gets +1/+0 and has vigilance as long as there are four or more card types among cards in your graveyard.

Dalkovan Packbeasts

Vigilance
Mobilize 3 (Whenever this creature attacks, create three tapped and attacking 1/1 red Warrior creature tokens. Sacrifice them at the beginning of the next end step.)

Bulwark Ox

Whenever this creature attacks while saddled, put a +1/+1 counter on target creature.
Sacrifice this creature: Creatures you control with counters on them gain hexproof and indestructible until end of turn.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Contraband Livestock

Exile target creature, then roll a d20.
1—9 | Its controller creates a 4/4 green Ox creature token.
10—19 | Its controller creates a 2/2 green Boar creature token.
20 | Its controller creates a 0/1 white Goat creature token.

Longhorn Firebeast

When this creature enters, any opponent may have it deal 5 damage to them. If a player does, sacrifice this creature.

Charging Cinderhorn

Haste
At the beginning of each player's end step, if no creatures attacked this turn, put a fury counter on this creature. Then this creature deals damage equal to the number of fury counters on it to that player.