Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Mountain

Midnight Guard

Whenever another creature enters, untap Midnight Guard.

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Ash Barrens

{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Presence of Gond

Enchant creature
Enchanted creature has "{T}: Create a 1/1 green Elf Warrior creature token."

Sprout Swarm

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.)
Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 green Saproling creature token.

Commune with the Gods

Reveal the top five cards of your library. You may put a creature or enchantment card from among them into your hand. Put the rest into your graveyard.

Angelic Purge

As an additional cost to cast this spell, sacrifice a permanent.
Exile target artifact, creature, or enchantment.

Evolving Wilds

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

Raise the Alarm

Create two 1/1 white Soldier creature tokens.

Plains

Nest Invader

When Nest Invader enters, create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Soul Warden

Whenever another creature enters, you gain 1 life.

Essence Warden

Forest

Nettle Sentinel

Nettle Sentinel doesn't untap during your untap step.
Whenever you cast a green spell, you may untap Nettle Sentinel.