Liberated Livestock

When Liberated Livestock 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 Holy Cow enters the battlefield, you gain 2 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Longhorn Firebeast

When Longhorn Firebeast enters the battlefield, any opponent may have it deal 5 damage to them. If a player does, sacrifice Longhorn Firebeast.

Bartered Cow

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

Earth-Origin Yak

When Earth-Origin Yak enters the battlefield, creatures you control get +1/+1 until end of turn.

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 Arc Runner.

Inquisitor's Ox

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

Bruse Tarl, Roving Rancher

Oxen you control have double strike.
Whenever Bruse Tarl, Roving Rancher enters the battlefield 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.

Charging Cinderhorn

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

Ox of Agonas

When Ox of Agonas enters the battlefield, 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.)
Ox of Agonas escapes with a +1/+1 counter on it.

Makindi Ox

Landfall — Whenever a land enters the battlefield under your control, tap target creature an opponent controls.

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 to a creature.)
Menace (This creature can't be blocked except by two or more creatures.)
Enchanted creature gets +3/+3 and has menace.