Keyword: Haste

Haste (This creature can attack and as soon as it comes under your control.)

Flying, haste

If an opponent controls a Plains and you control a Mountain, you may cast this spell without paying its mana cost.
Haste

Trample, haste

Haste
Whenever Lava Runner becomes the target of a spell or ability, that spell or ability’s controller sacrifices a land.

Haste
Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Avalanche Riders enters the battlefield, destroy target land.

Haste

Haste; horsemanship (This creature can’t be blocked except by creatures with horsemanship.)

Haste

Haste; horsemanship (This creature can’t be blocked except by creatures with horsemanship.)

Flying, haste

Haste (This creature can attack and as soon as it comes under your control.)

Haste (This creature can attack and as soon as it comes under your control.)

Haste

First strike, haste

Haste
Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Keldon Champion enters the battlefield, it deals 3 damage to target player or planeswalker.

Haste; horsemanship (This creature can’t be blocked except by creatures with horsemanship.)

Haste (This creature can attack and as soon as it comes under your control.)

Flying, haste

Haste

Haste (This creature can attack and as soon as it comes under your control.)
At the beginning of the end step, return Viashino Sandscout to its owner’s hand. (Return it only if it’s on the battlefield.)

Haste
Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Avalanche Riders enters the battlefield, destroy target land.

Haste (This creature can attack and as soon as it comes under your control.)

Flying, haste

Flying, haste