Keen Sense

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Season of Growth

Whenever a creature you control enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Whenever you cast a spell that targets a creature you control, draw a card.

Sol Ring

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Gruul Signet

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Mountain

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Forest

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Birds of Paradise

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Skyshroud Claim

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

Command Tower

Ancient Tomb

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

Taiga

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

The Howling Abomination

Haste
The Howling Abomination has trample as long as you've cast three or more spells this turn.
Whenever The Howling Abomination becomes the target of a spell, it gets +2/+2 until end of turn and deals 2 damage to each opponent.

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.