Ancient Greenwarden

Reach (This creature can block creatures with flying.)
You may play lands from your graveyard.
If a land entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Arcane Signet

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

Ramunap Excavator

Tireless Provisioner

Landfall — Whenever a land you control enters, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Glacierwood Siege

As this enchantment enters, choose Temur or Sultai.
• Temur — Whenever you cast an instant or sorcery spell, target player mills four cards.
• Sultai — You may play lands from your graveyard.

Tireless Tracker

Landfall — Whenever a land you control enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, put a +1/+1 counter on this creature.

Rampaging Baloths

Trample
Landfall — Whenever a land you control enters, create a 4/4 green Beast creature token.

Crucible of Worlds

Aesi, Tyrant of Gyre Strait

You may play an additional land on each of your turns.
Landfall — Whenever a land you control enters, you may draw a card.

Bonny Pall, Clearcutter

Reach
When Bonny Pall enters, create Beau, a legendary blue Ox creature token with "Beau's power and toughness are each equal to the number of lands you control."
Whenever you attack, draw a card, then you may put a land card from your hand or graveyard onto the battlefield.

Conduit of Worlds

You may play lands from your graveyard.
{T}: Choose target nonland permanent card in your graveyard. If you haven't cast a spell this turn, you may cast that card. If you do, you can't cast additional spells this turn. Activate only as a sorcery.

Aftermath Analyst

When this creature enters, mill three cards.
{3}{G}, Sacrifice this creature: Return all land cards from your graveyard to the battlefield tapped.

Scute Swarm

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

Springbloom Druid

When this creature enters, you may sacrifice a land. If you do, search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Icetill Explorer

You may play an additional land on each of your turns.
You may play lands from your graveyard.
Landfall — Whenever a land you control enters, mill a card.

Slogurk, the Overslime

Trample
Whenever a land card is put into your graveyard from anywhere, put a +1/+1 counter on Slogurk.
Remove three +1/+1 counters from Slogurk: Return it to its owner's hand.
When Slogurk leaves the battlefield, return up to three target land cards from your graveyard to your hand.

Sol Ring

Tatyova, Benthic Druid

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

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Titania, Protector of Argoth

When Titania enters, return target land card from your graveyard to the battlefield.
Whenever a land you control is put into a graveyard from the battlefield, create a 5/3 green Elemental creature token.

Erinis, Gloom Stalker

Deathtouch
Whenever Erinis attacks, return target land card from your graveyard to the battlefield.
Choose a Background (You can have a Background as a second commander.)

Kishla Skimmer

Flying
Whenever a card leaves your graveyard during your turn, draw a card. This ability triggers only once each turn.

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."