Wild Ox

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

Giant Ox

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

Earth-Origin Yak

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

Goldenhide Ox

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

Holy Cow

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

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.

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.

Zodiac Ox

Yoked Ox

Ox of Agonas

When Ox of Agonas 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.)
Ox of Agonas escapes with a +1/+1 counter on it.

Raging Bull

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.

Pillarfield Ox

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.")

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.

Bonny Pall, Clearcutter

Reach
When Bonny Pall, Clearcutter enters, create Beau, a legendary blue Ox creature token with "This creature's power and toughness are each equal to the number of lands you control."
Whenever you attack, draw a card, then you may put a land card from your hand or graveyard onto the battlefield.

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.

Beau

This creature's power and toughness are each equal to the number of lands you control.

Makindi Ox

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