Snow-Covered Mountain

Horn of Greed

Whenever a player plays a land, that player draws a card.

Seismic Strike

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Valakut, the Molten Pinnacle

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

Chandra, Awakened Inferno

This spell can't be countered.
+2: Each opponent gets an emblem with "At the beginning of your upkeep, this emblem deals 1 damage to you."
−3: Chandra deals 3 damage to each non-Elemental creature.
−X: Chandra deals X damage to target creature or planeswalker. If a permanent dealt damage this way would die this turn, exile it instead.

Spawn of Thraxes

Flying
When this creature enters, it deals damage to any target equal to the number of Mountains you control.

Storm Cauldron

Each player may play an additional land during each of their turns.
Whenever a land is tapped for mana, return it to its owner's hand.

Dwarven Mine

({T}: Add {R}.)
This land enters tapped unless you control three or more other Mountains.
When this land enters untapped, create a 1/1 red Dwarf creature token.

Skred

Skred deals damage to target creature equal to the number of snow permanents you control.

Rockslide Ambush

Rockslide Ambush deals damage to target creature equal to the number of Mountains you control.

Brand of Ill Omen

Enchant creature
Cumulative upkeep {R} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Enchanted creature's controller can't cast creature spells.

Spitting Earth

Spitting Earth deals damage to target creature equal to the number of Mountains you control.