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.)

Patient Naturalist

When Patient Naturalist enters, mill three cards. Put a land card from among the milled cards into your hand. If you can't, create a Treasure token. (To mill three cards, put the top three cards of your library into your graveyard.)

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.)

Mountain

Brimstone Roundup

Whenever you cast your second spell each turn, 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."
Plot {2}{R} (You may pay {2}{R} 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.)

Bristling Backwoods

Bristling Backwoods enters tapped.
When Bristling Backwoods enters, it deals 1 damage to target opponent.
{T}: Add {R} or {G}.

Spinewoods Paladin

Trample
When Spinewoods Paladin enters, you gain 3 life.
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.)

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.

Forest

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.)

Shepherd of the Clouds

Flying, vigilance
When Shepherd of the Clouds enters, return target permanent card with mana value 3 or less from your graveyard to your hand. Return that card to the battlefield instead if you control a Mount.

Plains

Eriette's Lullaby

Destroy target tapped creature. You gain 2 life.

Prickly Pair

When Prickly Pair 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."

Creosote Heath

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

Full Steam Ahead

Until end of turn, each creature you control gets +2/+2 and gains trample and "This creature can't be blocked by more than one creature."

Outlaws' Fury

Creatures you control get +2/+0 until end of turn. If you control an outlaw, exile the top card of your library. Until the end of your next turn, you may play that card. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Wanted Griffin

Flying
When Wanted Griffin dies, 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."

Abraded Bluffs

Abraded Bluffs enters tapped.
When Abraded Bluffs enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Mirage Mesa

Mirage Mesa enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Mine Raider

Trample
When Mine Raider enters, if you control another outlaw, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Arid Archway

Arid Archway enters tapped.
When Arid Archway enters, return a land you control to its owner's hand. If another Desert was returned this way, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}{C}.

Voracious Varmint

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

Trash the Town

Spree (Choose one or more additional costs.)
+ {2} — Put two +1/+1 counters on target creature.
+ {1} — Target creature gains trample until end of turn.
+ {1} — Until end of turn, target creature gains "Whenever this creature deals combat damage to a player, draw two cards."

Quilled Charger

Whenever Quilled Charger attacks while saddled, it gets +1/+2 and gains menace until end of turn. (It can't be blocked except by two or more 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.)

Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

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.