Calamity, Galloping Inferno

Haste
Whenever Calamity attacks while saddled, choose a nonlegendary creature that saddled it this turn and create a tapped and attacking token that's a copy of it. Sacrifice that token at the beginning of the next end step. Repeat this process once.
Saddle 1

Have

Rootbound Crag

This land enters tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

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.)

Possible Swap

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Colossification

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature gets +20/+20.

Split Up

Choose one —
• Destroy all tapped creatures.
• Destroy all untapped creatures.

Discerning Peddler

When this creature enters, you may discard a card. If you do, draw a card.

Relic of Legends

{T}: Add one mana of any color.
Tap an untapped legendary creature you control: Add one mana of any color.

Passionate Archaeologist

Commander creatures you own have "Whenever you cast a spell from exile, this creature deals damage equal to that spell's mana value to target opponent."

Don't Have

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Elspeth's Smite

Elspeth's Smite deals 3 damage to target attacking or blocking creature. If that creature would die this turn, exile it instead.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Dueling Grounds

No more than one creature can attack each combat.
No more than one creature can block each combat.

Helping Hand

Return target creature card with mana value 3 or less from your graveyard to the battlefield tapped.

Seek the Beast

Exile the top two cards of your library. Until your next end step, you may play those cards.

Questing Druid

Whenever you cast a spell that's white, blue, black, or red, put a +1/+1 counter on this creature.

Questing Druid // Seek the Beast

Blossoming Sands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {G} or {W}.

Vitalize

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Jaspera Sentinel

Reach
{T}, Tap an untapped creature you control: Add one mana of any color.

Survivors' Encampment

{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.

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.

Annie Joins Up

When Annie Joins Up enters, it deals 5 damage to target creature or planeswalker an opponent controls.
If a triggered ability of a legendary creature you control triggers, that ability triggers an additional time.

Ferocification

At the beginning of combat on your turn, choose one —
• Target creature you control gets +2/+0 until end of turn.
• Target creature you control gains menace and haste until end of turn.

Temple of Triumph

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {W}.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Temur Sabertooth

{1}{G}: You may return another creature you control to its owner's hand. If you do, this creature gains indestructible until end of turn.

Moon-Blessed Cleric

Divine Intervention — When this creature enters, you may search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Drover Grizzly

Whenever this creature 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.)

Bridled Bighorn

Vigilance
Whenever this creature attacks while saddled, create a 1/1 white Sheep creature token.
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.)

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Forest

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Final Showdown

Spree (Choose one or more additional costs.)
+ {1} — All creatures lose all abilities until end of turn.
+ {1} — Choose a creature you control. It gains indestructible until end of turn.
+ {3}{W}{W} — Destroy all creatures.

High Noon

Each player can't cast more than one spell each turn.
{4}{R}, Sacrifice this enchantment: It deals 5 damage to any target.

Temple of Plenty

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{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."

Bristling Backwoods

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

Rith's Grove

When this land enters, sacrifice it unless you return a non-Lair land you control to its owner's hand.
{T}: Add {R}, {G}, or {W}.

One Last Job

Spree (Choose one or more additional costs.)
+ {2} — Return target creature card from your graveyard to the battlefield.
+ {1} — Return target Mount or Vehicle card from your graveyard to the battlefield.
+ {1} — Return target Aura or Equipment card from your graveyard to the battlefield attached to a creature you control.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Heliod's Intervention

Choose one —
• Destroy X target artifacts and/or enchantments.
• Target player gains twice X life.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

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.

Atraxa's Fall

Destroy target artifact, battle, enchantment, or creature with flying.

Game Trail

As this land enters, you may reveal a Mountain or Forest card from your hand. If you don't, this land enters tapped.
{T}: Add {R} or {G}.

Rustler Rampage

Spree (Choose one or more additional costs.)
+ {1} — Untap all creatures target player controls.
+ {1} — Target creature gains double strike until end of turn.

Chained to the Rocks

Enchant Mountain you control
When this Aura enters, exile target creature an opponent controls until this Aura leaves the battlefield. (That creature returns under its owner's control.)

Emerald Charm

Choose one —
• Untap target permanent.
• Destroy target non-Aura enchantment.
• Target creature loses flying until end of turn.

Gleam of Resistance

Creatures you control get +1/+2 until end of turn. Untap those creatures.
Basic landcycling {1}{W} ({1}{W}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Trained Arynx

Whenever this creature 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.)

Saruli Caretaker

Defender
{T}, Tap an untapped creature you control: Add one mana of any color.

Obelisk of Naya

Annie Flash, the Veteran

Flash
When Annie Flash enters, if you cast it, return target permanent card with mana value 3 or less from your graveyard to the battlefield tapped.
Whenever Annie Flash becomes tapped, exile the top two cards of your library. You may play those cards this turn.

Wylie Duke, Atiin Hero

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

Explosive Derailment

Spree (Choose one or more additional costs.)
+ {2} — Explosive Derailment deals 4 damage to target creature.
+ {2} — Destroy target artifact.

Outcaster Greenblade

When this creature enters, search your library for a basic land card or a Desert card, reveal it, put it into your hand, then shuffle.
This creature gets +1/+1 for each Desert you control.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Cabaretti Courtyard

When this land enters, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Rambling Possum

Whenever this creature 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.)

Quest for Renewal

Whenever a creature you control becomes tapped, you may put a quest counter on this enchantment.
As long as there are four or more quest counters on this enchantment, untap all creatures you control during each other player's untap step.

Audacity

Enchant creature
Enchanted creature gets +2/+0 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
When this Aura is put into a graveyard from the battlefield, draw a card.

Command Tower

Thunder Lasso

When this Equipment 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}

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.

Intrepid Stablemaster

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

Quick Draw

Target creature you control gets +1/+1 and gains first strike until end of turn. Creatures target opponent controls lose first strike and double strike until end of turn.

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Plains

Shepherd of the Clouds

Flying, vigilance
When this creature 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.

Sundown Pass

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {W}.

Sol Ring

Fortune, Loyal Steed

When Fortune enters, scry 2.
Whenever Fortune attacks while saddled, at end of combat, exile it and up to one creature that saddled it this turn, then return those cards to the battlefield under their owner's control.
Saddle 1

Angel

Escape to the Wilds

Exile the top five cards of your library. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Sunpetal Grove

This land enters tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Mystical Tether

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

Quilled Charger

Whenever this creature 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.)

Irascible Wolverine

When this creature enters, exile the top card of your library. Until end of turn, you may play that card.
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.)

Sheep

Ankle Biter

Seraphic Steed

First strike, lifelink
Whenever this creature 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.)

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Highway Robbery

You may discard a card or sacrifice a land. If you do, draw two cards.
Plot {1}{R} (You may pay {1}{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.)

Selvala, Eager Trailblazer

Vigilance
Whenever you cast a creature spell, 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."
{T}: Choose a color. Add one mana of that color for each different power among creatures you control.

Scorching Shot

Scorching Shot deals 5 damage to target creature.

Creosote Heath

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

Miriam, Herd Whisperer

During your turn, Mounts and Vehicles you control have hexproof.
Whenever a Mount or Vehicle you control attacks, put a +1/+1 counter on it.

Sterling Grove

Other enchantments you control have shroud. (They can't be the targets of spells or abilities.)
{1}, Sacrifice this enchantment: Search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Wulfgar of Icewind Dale

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
If a creature you control attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Buried in the Garden

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

Gila Courser

Whenever this creature attacks while saddled, exile the top card of your library. Until the end of your next turn, you may play that card.
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.)

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Bounding Felidar

Whenever this creature 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.)

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Shapers' Sanctuary

Whenever a creature you control becomes the target of a spell or ability an opponent controls, you may draw a card.