Shock

Highland Forest

({T}: Add {R} or {G}.)
Highland Forest enters tapped.

Kazandu Stomper

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
When Kazandu Stomper enters, return up to two lands you control to their owner's hand.

Akoum Hellhound

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

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 Nectarpot

Landfall — Whenever a land you control enters, you gain 1 life.

Mountain

Honey Mammoth

When Honey Mammoth enters, you gain 4 life.

Crash Through

Creatures you control gain trample until end of turn. (Each of those creature can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

Charge Through

Target creature gains trample until end of turn.
Draw a card.

Goblin Arsonist

When Goblin Arsonist dies, you may have it deal 1 damage to any target.

Arachnoform

Enchant creature
Enchanted creature gets +2/+2, has reach, and is every creature type.

Spitfire Lagac

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

Evolving Wilds

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

Hydra's Growth

Enchant creature
When Hydra's Growth enters, put a +1/+1 counter on enchanted creature.
At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.