Retreat to Kazandu

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Put a +1/+1 counter on target creature.
• You gain 2 life.

Nesting Dragon

Flying
Landfall — Whenever a land enters the battlefield under your control, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature gets +1/+0 until end of turn.'"

Sol Ring

Arcane Signet

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

Vexing Shusher

This spell can't be countered.
{R/G}: Target spell can't be countered.

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Scute Swarm

Landfall — Whenever a land enters the battlefield under your control, create a 1/1 green Insect creature token. If you control six or more lands, create a token that's a copy of Scute Swarm instead.

Gruul Turf

Gruul Turf enters the battlefield tapped.
When Gruul Turf enters the battlefield, return a land you control to its owner's hand.
{T}: Add {R}{G}.

Gruul Signet

Kodama of the East Tree

Reach
Whenever another permanent enters the battlefield under your control, if it wasn't put onto the battlefield with this ability, you may put a permanent card with equal or lesser mana value from your hand onto the battlefield.
Partner (You can have two commanders if both have partner.)

Ancient Greenwarden

Reach
You may play lands from your graveyard.
If a land entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Omnath, Locus of Rage

Landfall — Whenever a land enters the battlefield under your control, create a 5/5 red and green Elemental creature token.
Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

Spitfire Lagac

Landfall — Whenever a land enters the battlefield under your control, Spitfire Lagac deals 1 damage to each opponent.

Tunneling Geopede

Landfall — Whenever a land enters the battlefield under your control, Tunneling Geopede deals 1 damage to each opponent.

Guildless Commons

Guildless Commons enters the battlefield tapped.
When Guildless Commons enters the battlefield, return a land you control to its owner's hand.
{T}: Add {C}{C}.

Toggo, Goblin Weaponsmith

Landfall — Whenever a land enters the battlefield under your control, create a colorless Equipment artifact token named Rock with "Equipped creature has '{1}, {T}, Sacrifice Rock: This creature deals 2 damage to any target'" and equip {1}.
Partner (You can have two commanders if both have partner.)

Avenger of Zendikar

When Avenger of Zendikar enters the battlefield, create a 0/1 green Plant creature token for each land you control.
Landfall — Whenever a land enters the battlefield under your control, you may put a +1/+1 counter on each Plant creature you control.

Reckless Fireweaver

Whenever an artifact enters the battlefield under your control, Reckless Fireweaver deals 1 damage to each opponent.

Radha, Heart of Keld

As long as it's your turn, Radha, Heart of Keld has first strike.
You may look at the top card of your library any time, and you may play lands from the top of your library.
{4}{R}{G}: Radha gets +X/+X until end of turn, where X is the number of lands you control.

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Lotus Cobra

Landfall — Whenever a land enters the battlefield under your control, add one mana of any color.