Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Moraug, Fury of Akoum

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land you control enters, if it's your main phase, there's an additional combat phase after this phase. At the beginning of that combat, untap all creatures you control.

Mountain

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Brushfire Elemental

Haste
Brushfire Elemental can't be blocked by creatures with power 2 or less.
Landfall — Whenever a land you control enters, Brushfire Elemental gets +2/+2 until end of turn.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

Skyclave Geopede

Trample
Landfall — Whenever a land you control enters, Skyclave Geopede gets +2/+2 until end of turn.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Horizon Canopy

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Horizon Canopy: Draw a card.

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Territorial Scythecat

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on Territorial Scythecat.

Canopy Baloth

Landfall — Whenever a land you control enters, Canopy Baloth gets +2/+2 until end of turn.

Scute Swarm

Landfall — Whenever a land you control enters, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Makindi Ox

Landfall — Whenever a land you control enters, tap target creature an opponent controls.

Omnath, Locus of Creation

When Omnath, Locus of Creation enters, draw a card.
Landfall — Whenever a land you control enters, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Spire Garden

Spire Garden enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Skyclave Squid

Defender
Landfall — Whenever a land you control enters, Skyclave Squid can attack this turn as though it didn't have defender.

Forest

Wasteland

{T}: Add {C}.
{T}, Sacrifice Wasteland: Destroy target nonbasic land.

Island

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Plains

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Avenger of Zendikar

When Avenger of Zendikar enters, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land you control enters, you may put a +1/+1 counter on each Plant creature you control.

Felidar Retreat

Landfall — Whenever a land you control enters, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Lotus Cobra

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

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Bountiful Promenade

Bountiful Promenade enters tapped unless you have two or more opponents.
{T}: Add {G} or {W}.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Copperline Gorge

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

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Razorverge Thicket

Razorverge Thicket enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Spitfire Lagac

Landfall — Whenever a land you control enters, this creature deals 1 damage to each opponent.

Canyon Jerboa

Landfall — Whenever a land you control enters, creatures you control get +1/+1 until end of turn.

Fearless Fledgling

Landfall — Whenever a land you control enters, put a +1/+1 counter on Fearless Fledgling. It gains flying until end of turn.

Prismatic Vista

{T}, Pay 1 life, Sacrifice Prismatic Vista: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Celestial Colonnade

Celestial Colonnade enters tapped.
{T}: Add {W} or {U}.
{3}{W}{U}: Until end of turn, Celestial Colonnade becomes a 4/4 white and blue Elemental creature with flying and vigilance. It's still a land.

Admonition Angel

Flying
Landfall — Whenever a land you control enters, you may exile target nonland permanent other than Admonition Angel.
When Admonition Angel leaves the battlefield, return all cards exiled with it to the battlefield under their owners' control.

Windswept Heath

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Grove of the Burnwillows

{T}: Add {C}.
{T}: Add {R} or {G}. Each opponent gains 1 life.

Arid Mesa

{T}, Pay 1 life, Sacrifice Arid Mesa: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

Phylath, World Sculptor

When Phylath, World Sculptor enters, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land you control enters, put four +1/+1 counters on target Plant you control.

Kazandu Valley

Kazandu Valley enters tapped.
{T}: Add {G}.

Kazandu Mammoth

Landfall — Whenever a land you control enters, Kazandu Mammoth gets +2/+2 until end of turn.

Kazandu Mammoth // Kazandu Valley

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Valakut Exploration

Landfall — Whenever a land you control enters, exile the top card of your library. You may play that card for as long as it remains exiled.
At the beginning of your end step, if there are cards exiled with Valakut Exploration, put them into their owner's graveyard, then Valakut Exploration deals that much damage to each opponent.

Prowling Felidar

Vigilance
Landfall — Whenever a land you control enters, put a +1/+1 counter on Prowling Felidar.

Akoum Hellhound

Landfall — Whenever a land you control enters, Akoum Hellhound gets +2/+2 until end of turn.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.