Giant Ox

Giant Ox crews Vehicles using its toughness rather than its power.

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.

Wild Ox

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

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.")

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.

Ironhoof Ox

Ironhoof Ox can't be blocked by more than one creature.

Makindi Ox

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

Hungry Hungry Heifer

At the beginning of your upkeep, you may remove a counter from a permanent you control. If you don't, sacrifice Hungry Hungry Heifer.

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.

Yoked Ox

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.

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.

Zodiac Ox

Krazy Kow

At the beginning of your upkeep, roll a six-sided die. If you a roll a 1, sacrifice Krazy Kow and it deals 3 damage to each creature and each player.

Goldenhide Ox

Constellation — Whenever Goldenhide Ox or another enchantment enters the battlefield under your control, target creature must be blocked this turn if able.

Raging Bull

Pillarfield Ox

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.

Earth-Origin Yak

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

Stampede Rider

Trample
At the beginning of each combat, if you control a creature with power 4 or greater, Stampede Rider gets +1/+1 until end of turn.