Railway Brawler

Reach, trample
Whenever another creature you control enters, put X +1/+1 counters on it, where X is its power.
Plot {3}{G} (You may pay {3}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Ankle Biter

Forest

Acrobatic Leap

Target creature gets +1/+3 and gains flying until end of turn. Untap it.

Bristlepack Sentry

Defender
As long as you control a creature with power 4 or greater, Bristlepack Sentry can attack as though it didn't have defender.

Gruff Triplets

Trample
When Gruff Triplets enters, if it isn't a token, create two tokens that are copies of it.
When Gruff Triplets dies, put a number of +1/+1 counters equal to its power on each creature you control named Gruff Triplets.

Seraphic Steed

First strike, lifelink
Whenever Seraphic Steed attacks while saddled, create a 3/3 white Angel creature token with flying.
Saddle 4 (Tap any number of other creatures you control with total power 4 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Giant Beaver

Vigilance
Whenever Giant Beaver attacks while saddled, put a +1/+1 counter on target creature that saddled it this turn.
Saddle 3 (Tap any number of other creatures you control with total power 3 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Bounding Felidar

Whenever Bounding Felidar attacks while saddled, put a +1/+1 counter on each other creature you control. You gain 1 life for each of those creatures.
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Throw from the Saddle

Target creature you control gets +1/+1 until end of turn. Put a +1/+1 counter on it instead if it's a Mount. Then it deals damage equal to its power to target creature you don't control.

Lush Portico

({T}: Add {G} or {W}.)
Lush Portico enters tapped.
When Lush Portico enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Creosote Heath

Creosote Heath enters tapped.
When Creosote Heath enters, it deals 1 damage to target opponent.
{T}: Add {G} or {W}.

Cooped Up

Enchant creature
Enchanted creature can't attack or block.
{2}{W}: Exile enchanted creature.

Wylie Duke, Atiin Hero

Vigilance
Whenever Wylie Duke, Atiin Hero becomes tapped, you gain 1 life and draw a card.

Vengeful Townsfolk

Whenever one or more other creatures you control die, put a +1/+1 counter on Vengeful Townsfolk.

Thousand Moons Infantry

Untap Thousand Moons Infantry during each other player's untap step.

Pick Your Poison

Choose one —
• Each opponent sacrifices an artifact.
• Each opponent sacrifices an enchantment.
• Each opponent sacrifices a creature with flying.

Ornery Tumblewagg

At the beginning of combat on your turn, put a +1/+1 counter on target creature.
Whenever Ornery Tumblewagg attacks while saddled, double the number of +1/+1 counters on target creature.
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Intrepid Stablemaster

Reach
{T}: Add {G}.
{T}: Add two mana of any one color. Spend this mana only to cast Mount or Vehicle spells.

Outcaster Trailblazer

When Outcaster Trailblazer enters, add one mana of any color.
Whenever another creature you control with power 4 or greater enters, draw a card.
Plot {2}{G} (You may pay {2}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Drover Grizzly

Whenever Drover Grizzly attacks while saddled, creatures you control gain trample 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.)

Plains

Steer Clear

Steer Clear deals 2 damage to target attacking or blocking creature. Steer Clear deals 4 damage to that creature instead if you controlled a Mount as you cast this spell.

Moment of Valor

Choose one —
• Untap target creature. It gets +1/+0 and gains indestructible until end of turn.
• Destroy target creature with power 4 or greater.