Trained Arynx

Whenever Trained Arynx attacks while saddled, it gains first strike until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
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.)

Bovine Intervention

Destroy target artifact or creature. Its controller creates a 2/2 white Ox creature token.

Clear Shot

Target creature you control gets +1/+1 until end of turn. It deals damage equal to its power to target creature you don't control.

Rambling Possum

Whenever Rambling Possum attacks while saddled, it gets +1/+2 until end of turn. Then you may return any number of creatures that saddled it this turn to their owner's hand.
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.)

Swamp

Freestrider Commando

Freestrider Commando enters with two +1/+1 counters on it if it wasn't cast or no mana was spent to cast it.
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.)

Shifting Grift

Spree (Choose one or more additional costs.)
+ {2} — Exchange control of two target creatures.
+ {1} — Exchange control of two target artifacts.
+ {1} — Exchange control of two target enchantments.

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Forest

Back for More

Return target creature card from your graveyard to the battlefield. When you do, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.)

Mourner's Surprise

Return up to one target creature card from your graveyard to your hand. Create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Thunder Lasso

When Thunder Lasso enters, attach it to target creature you control.
Equipped creature gets +1/+1.
Whenever equipped creature attacks, tap target creature defending player controls.
Equip {2}

Stubborn Burrowfiend

Whenever Stubborn Burrowfiend becomes saddled for the first time each turn, mill two cards, then Stubborn Burrowfiend gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.
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.)

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.

Badlands Revival

Return up to one target creature card from your graveyard to the battlefield. Return up to one target permanent card from your graveyard to your hand.

Stagecoach Security

When Stagecoach Security enters, creatures you control get +1/+1 and gain vigilance until end of turn.
Plot {3}{W} (You may pay {3}{W} 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.)

Smuggler's Surprise

Spree (Choose one or more additional costs.)
+ {2} — Mill four cards. You may put up to two creature and/or land cards from among the milled cards into your hand.
+ {4}{G} — You may put up to two creature cards from your hand onto the battlefield.
+ {1} — Creatures you control with power 4 or greater gain hexproof and indestructible until end of turn.

Sterling Keykeeper

Spinewoods Armadillo

Reach
Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
{1}{G}, Discard Spinewoods Armadillo: Search your library for a basic land card or a Desert card, reveal it, put it into your hand, then shuffle. You gain 3 life.

Outlaw Medic

Lifelink
When Outlaw Medic dies, draw a card.

Prosperity Tycoon

When Prosperity Tycoon enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
{2}, Sacrifice a token: Prosperity Tycoon gains indestructible until end of turn. Tap it. (Damage and effects that say "destroy" don't destroy it.)

Cactarantula

This spell costs {1} less to cast if you control a Desert.
Reach
Whenever Cactarantula becomes the target of a spell or ability an opponent controls, you may draw a card.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Contagion Engine

When Contagion Engine enters, put a -1/-1 counter on each creature target player controls.
{4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Congregation Gryff

Flying, lifelink
Whenever Congregation Gryff attacks while saddled, it gets +X/+X until end of turn, where X is the number of Mounts you control.
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.)

Voracious Varmint

Vigilance
{1}, Sacrifice Voracious Varmint: Destroy target artifact or enchantment.

Honest Rutstein

When Honest Rutstein enters, return target creature card from your graveyard to your hand.
Creature spells you cast cost {1} less to cast.

Inventive Wingsmith

At the beginning of your end step, if you haven't cast a spell from your hand this turn and Inventive Wingsmith doesn't have a flying counter on it, put a flying counter on it.

Buried in the Garden

Enchant land
When Buried in the Garden enters, exile target nonland permanent you don't control until Buried in the Garden leaves the battlefield.
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Mystical Tether

You may cast Mystical Tether as though it had flash if you pay {2} more to cast it.
When Mystical Tether enters, exile target artifact or creature an opponent controls until Mystical Tether leaves the battlefield.

Ankle Biter

Ambush Gigapede

Flash
When Ambush Gigapede enters, target creature an opponent controls gets -2/-2 until end of turn.

Eriette's Lullaby

Destroy target tapped creature. You gain 2 life.

Festering Gulch

Festering Gulch enters tapped.
When Festering Gulch enters, it deals 1 damage to target opponent.
{T}: Add {B} or {G}.

Prairie Dog

Lifelink
At the beginning of your end step, if you haven't cast a spell from your hand this turn, put a +1/+1 counter on Prairie Dog.
{4}{W}: Until end of turn, if you would put one or more +1/+1 counters on a creature you control, put that many plus one +1/+1 counters on it instead.