Case of the Locked Hothouse

You may play an additional land on each of your turns.
To solve — You control seven or more lands. (If unsolved, solve at the beginning of your end step.)
Solved — You may look at the top card of your library any time, and you may play lands and cast creature and enchantment spells from the top of your library.

Grothama, All-Devouring

Other creatures have "Whenever this creature attacks, you may have it fight Grothama, All-Devouring."
When Grothama leaves the battlefield, each player draws cards equal to the amount of damage dealt to Grothama this turn by sources they controlled.

Raging Ravine

Raging Ravine enters tapped.
{T}: Add {R} or {G}.
{2}{R}{G}: Until end of turn, Raging Ravine becomes a 3/3 red and green Elemental creature with "Whenever this creature attacks, put a +1/+1 counter on it." It's still a land.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Thran Dynamo

Forest

Esika's Chariot

When Esika's Chariot enters, create two 2/2 green Cat creature tokens.
Whenever Esika's Chariot attacks, create a token that's a copy of target token you control.
Crew 4

Wandertale Mentor

Whenever you expend 4, put a +1/+1 counter on Wandertale Mentor. (You expend 4 as you spend your fourth total mana to cast spells during a turn.)
{T}: Add {R} or {G}.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Smuggler's Buggy

Hideaway 4 (When this artifact enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Whenever Smuggler's Buggy deals combat damage to a player, you may cast the exiled card without paying its mana cost. If you do, return Smuggler's Buggy to its owner's hand.
Crew 2

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Zendikar Resurgent

Whenever you tap a land for mana, add one mana of any type that land produced. (The types of mana are white, blue, black, red, green, and colorless.)
Whenever you cast a creature spell, draw a card.

Primeval Bounty

Whenever you cast a creature spell, create a 3/3 green Beast creature token.
Whenever you cast a noncreature spell, put three +1/+1 counters on target creature you control.
Landfall — Whenever a land you control enters, you gain 3 life.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Skitterbeam Battalion

Prototype {3}{R}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Trample, haste
When Skitterbeam Battalion enters, if you cast it, create two tokens that are copies of it.

Command Tower

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

Fungus Frolic

Create two 1/1 green Saproling creature tokens. (Then exile this card. You may cast the creature later from exile.)

Brightcap Badger

Each Fungus and Saproling you control has "{T}: Add {G}."
At the beginning of your end step, create a 1/1 green Saproling creature token.

Brightcap Badger // Fungus Frolic

Rootbound Crag

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

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Mossfire Valley

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Gimli's Reckless Might

Creatures you control have haste.
Formidable — Whenever you attack, if creatures you control have total power 8 or greater, target attacking creature you control fights up to one target creature you don't control.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Untethered Express

Trample
Whenever Untethered Express attacks, put a +1/+1 counter on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Wooded Ridgeline

({T}: Add {R} or {G}.)
Wooded Ridgeline enters tapped.

Temple of Abandon

Temple of Abandon enters tapped.
When Temple of Abandon enters, scry 1.
{T}: Add {R} or {G}.

Game Trail

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

Molten Echoes

As Molten Echoes enters, choose a creature type.
Whenever a nontoken creature you control of the chosen type enters, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Reliquary Tower

Xenagos, God of Revels

Indestructible
As long as your devotion to red and green is less than seven, Xenagos isn't a creature.
At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Rampant Growth

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

Trailtracker Scout

{T}: Add one mana of any color.
Whenever you expend 8, return up to one target permanent card from your graveyard to your hand. (You expend 8 as you spend your eighth total mana to cast spells during a turn.)

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Mountain

Sight of the Scalelords

At the beginning of combat on your turn, creatures you control with toughness 4 or greater get +2/+2 and gain vigilance until end of turn.

Sol Ring

Llanowar Loamspeaker

{T}: Add one mana of any color.
{T}: Target land you control becomes a 3/3 Elemental creature with haste until end of turn. It's still a land. Activate only as a sorcery.

Threefold Thunderhulk

Threefold Thunderhulk enters with three +1/+1 counters on it.
Whenever Threefold Thunderhulk enters or attacks, create a number of 1/1 colorless Gnome artifact creature tokens equal to its power.
{2}, Sacrifice another artifact: Put a +1/+1 counter on Threefold Thunderhulk.

Tempt with Discovery

Tempting offer — Search your library for a land card and put it onto the battlefield. Each opponent may search their library for a land card and put it onto the battlefield. For each opponent who searches a library this way, search your library for a land card and put it onto the battlefield. Then each player who searched a library this way shuffles.

Gilded Lotus

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Glorious Sunrise

At the beginning of combat on your turn, choose one —
• Creatures you control get +1/+1 and gain trample until end of turn.
• Target land gains "{T}: Add {G}{G}{G}" until end of turn.
• Draw a card if you control a creature with power 3 or greater.
• You gain 3 life.

Open the Way

X can't be greater than the number of players in the game.
Reveal cards from the top of your library until you reveal X land cards. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Gruul Turf

Gruul Turf enters tapped.
When Gruul Turf enters, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Exotic Orchard

Ghalta, Primal Hunger

This spell costs {X} less to cast, where X is the total power of creatures you control.
Trample

Midnight Crusader Shuttle

Midnight Entity — Whenever Midnight Crusader Shuttle attacks, defending player faces a villainous choice — That player sacrifices a creature, or you gain control of a creature of your choice that player controls until end of turn. If you gain control of a creature this way, tap it, and it's attacking that player.
Crew 2

Blaster, Morale Booster

Modular 3
{X}, {T}: Move X +1/+1 counters from Blaster onto another target artifact. That artifact gains haste until end of turn. If Blaster has no +1/+1 counters on it, convert it. Activate only as a sorcery.

Blaster, Combat DJ

More Than Meets the Eye {1}{R}{G} (You may cast this card converted for {1}{R}{G}.)
Other nontoken artifact creatures and Vehicles you control have modular 1. (They enter with an additional +1/+1 counter on them. When they die, you may put their +1/+1 counters on target artifact creature.)
Whenever you put one or more +1/+1 counters on Blaster, convert it.

Blaster, Combat DJ // Blaster, Morale Booster

Skysovereign, Consul Flagship

Flying
Whenever Skysovereign, Consul Flagship enters or attacks, it deals 3 damage to target creature or planeswalker an opponent controls.
Crew 3 (Tap any number of creatures you control with total power 3 or more: This Vehicle becomes an artifact creature until end of turn.)

Bello, Bard of the Brambles

During your turn, each non-Equipment artifact and non-Aura enchantment you control with mana value 4 or greater is a 4/4 Elemental creature in addition to its other types and has indestructible, haste, and "Whenever this creature deals combat damage to a player, draw a card."

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Tranquil Thicket

Tranquil Thicket enters tapped.
{T}: Add {G}.
Cycling {G} ({G}, Discard this card: Draw a card.)

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Nature's Will

Whenever one or more creatures you control deal combat damage to a player, tap all lands that player controls and untap all lands you control.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Bootleggers' Stash

Lands you control have "{T}: Create a Treasure token."

Garruk's Uprising

When Garruk's Uprising enters, if you control a creature with power 4 or greater, draw a card.
Creatures you control have trample.
Whenever a creature you control with power 4 or greater enters, draw a card.

Explore

You may play an additional land this turn.
Draw a card.

Arcane Signet

Path of Discovery

Whenever a creature you control enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Canoptek Spyder

Flying
Fabricator Claw Array — Whenever another nontoken artifact creature or Vehicle you control enters, draw a card.

Thickest in the Thicket

When Thickest in the Thicket enters, put X +1/+1 counters on target creature, where X is that creature's power.
At the beginning of your end step, draw two cards if you control the creature with the greatest power or tied for the greatest power.

Thunderhawk Gunship

Flying
When Thunderhawk Gunship enters, create two 2/2 white Astartes Warrior creature tokens with vigilance.
Whenever Thunderhawk Gunship attacks, attacking creatures you control gain flying until end of turn.
Crew 2

Goliath Truck

Stowage — Whenever Goliath Truck attacks, put two +1/+1 counters on another target attacking creature.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Mosswort Bridge enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Cybership

Flying
Whenever Cybership deals combat damage to a player, put the top two cards of that player's library onto the battlefield face down under your control. They're 2/2 Cyberman artifact creatures.
Crew 4

Kodama of the East Tree

Reach
Whenever another permanent you control enters, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Nylea, God of the Hunt

Indestructible
As long as your devotion to green is less than five, Nylea isn't a creature. (Each {G} in the mana costs of permanents you control counts toward your devotion to green.)
Other creatures you control have trample.
{3}{G}: Target creature gets +2/+2 until end of turn.

Sheltered Thicket

({T}: Add {R} or {G}.)
Sheltered Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Forgotten Cave

Forgotten Cave enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Rolling Hamsphere

Rolling Hamsphere gets +1/+1 for each Hamster you control.
Whenever Rolling Hamsphere attacks, create three 1/1 red Hamster creature tokens, then it deals X damage to any target, where X is the number of Hamsters you control.
Crew 3

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Hoard Hauler

Trample
Whenever Hoard Hauler deals combat damage to a player, create a Treasure token for each artifact they control.
Crew 3

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.