Motivated Pony

Trample, haste
Whenever this creature attacks, attacking creatures get +1/+1 until end of turn. If a Food entered under your control this turn, untap those creatures and they get an additional +2/+2 until end of turn.

Breaching Hippocamp

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, untap another target creature you control.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Cobbled Lancer

As an additional cost to cast this spell, exile a creature card from your graveyard.
{3}{U}, Exile this card from your graveyard: Draw a card.

Clockwork Steed

This creature enters with four +1/+0 counters on it.
This creature can't be blocked by artifact creatures.
At end of combat, if this creature attacked or blocked this combat, remove a +1/+0 counter from it.
{X}, {T}: Put up to X +1/+0 counters on this creature. This ability can't cause the total number of +1/+0 counters on this creature to be greater than four. Activate only during your upkeep.

Vine Mare

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked by black creatures.

Thundermare

Haste (This creature can attack and {T} as soon as it comes under your control.)
When this creature enters, tap all other creatures.

Diamond Mare

As this creature enters, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Tarpan

When this creature dies, you gain 1 life.

Bronze Horse

Trample
As long as you control another creature, prevent all damage that would be dealt to this creature by spells that target it.

Thundering Mightmare

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Phantasmal Mount

Flying
{T}: Target creature you control with toughness 2 or less gets +1/+1 and gains flying until end of turn. When this creature leaves the battlefield this turn, sacrifice that creature. When the creature leaves the battlefield this turn, sacrifice this creature.

Surge Mare

This creature can't be blocked by green creatures.
Whenever this creature deals damage to an opponent, you may draw a card. If you do, discard a card.
{1}{U}: This creature gets +2/-2 until end of turn.

Temur Charger

Morph—Reveal a green card in your hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, target creature gains trample until end of turn.

Carnival Hellsteed

First strike, haste
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Zodiac Horse

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Shield Mare

This creature can't be blocked by red creatures.
When this creature enters or becomes the target of a spell or ability an opponent controls, you gain 3 life.

Lightning Mare

This spell can't be countered.
This creature can't be blocked by blue creatures.
{1}{R}: This creature gets +1/+0 until end of turn.

Chrome Steed

Metalcraft — This creature gets +2/+2 as long as you control three or more artifacts.

Armored Warhorse

Cosmos Charger

Flash
Flying
Foretelling cards from your hand costs {1} less and can be done on any player's turn.
Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Akroan Horse

Defender
When this creature enters, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Timbermare

Haste
Echo {5}{G} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, tap all other creatures.

Plague Mare

This creature can't be blocked by white creatures.
When this creature enters, creatures your opponents control get -1/-1 until end of turn.

Phantom Steed

Flash
When this creature enters, exile another target creature you control until this creature leaves the battlefield.
Whenever this creature attacks, create a tapped and attacking token that's a copy of the exiled card, except it's an Illusion in addition to its other types. Sacrifice that token at end of combat.

Sacred Prey

Whenever this creature becomes blocked, you gain 1 life.

Underworld Charger

This creature can't block.
Escape—{4}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)
This creature escapes with two +1/+1 counters on it.

Shadowfax, Lord of Horses

Horses you control have haste. (They can attack and {T} as soon as they come under your control.)
Whenever Shadowfax attacks, you may put a creature card with lesser power from your hand onto the battlefield tapped and attacking.