Gruul Signet

Yavimaya Dryad

Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
When Yavimaya Dryad enters, you may search your library for a Forest card, put it onto the battlefield tapped under target player's control, then shuffle.

Arbor Elf

Kamahl, Heart of Krosa

At the beginning of combat on your turn, creatures you control get +3/+3 and gain trample until end of turn.
{1}{G}: Until end of turn, target land you control becomes a 1/1 Elemental creature with vigilance, indestructible, and haste. It's still a land.
Partner (You can have two commanders if both have partner.)

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Migration Path

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

Harvester Druid

{T}: Add one mana of any color that a land you control could produce.

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.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Elvish Rejuvenator

When Elvish Rejuvenator enters, look at the top five cards of your library. You may put a land card from among them onto the battlefield tapped. Put the rest on the bottom of your library in a random order.

Llanowar Scout

{T}: You may put a land card from your hand onto the battlefield.

Radha, Heir to Keld

Whenever Radha, Heir to Keld attacks, you may add {R}{R}.
{T}: Add {G}.

Sakura-Tribe Scout

Krosan Restorer

{T}: Untap target land.
Threshold — {T}: Untap up to three target lands. Activate only if seven or more cards are in your graveyard.

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Fyndhorn Elves

Skyshroud Claim

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

Llanowar Elves

Wood Elves

When Wood Elves enters, search your library for a Forest card, put that card onto the battlefield, then shuffle.

Explore

You may play an additional land this turn.
Draw a card.

Arcane Signet

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

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sol Ring

Elvish Mystic

Talisman of Impulse

{T}: Add {C}.
{T}: Add {R} or {G}. Talisman of Impulse deals 1 damage to you.

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Jeska, Thrice Reborn

Jeska, Thrice Reborn enters with a loyalty counter on her for each time you've cast a commander from the command zone this game.
0: Choose target creature. Until your next turn, if that creature would deal combat damage to one of your opponents, it deals triple that damage to that player instead.
−X: Jeska, Thrice Reborn deals X damage to each of up to three targets.
Jeska, Thrice Reborn can be your commander.
Partner

Mina and Denn, Wildborn

You may play an additional land on each of your turns.
{R}{G}, Return a land you control to its owner's hand: Target creature gains trample until end of turn.