Plains

Sol Ring

Druid Class

(Gain the next level as a sorcery to add its ability.)
Landfall — Whenever a land you control enters, you gain 1 life.
{2}{G}: Level 2
You may play an additional land on each of your turns.
{4}{G}: Level 3
When this Class becomes level 3, target land you control becomes a creature with haste and "This creature's power and toughness are each equal to the number of lands you control." It's still a land.

Fearless Fledgling

Landfall — Whenever a land you control enters, put a +1/+1 counter on Fearless Fledgling. It gains flying until end of turn.

Island

Elfsworn Giant

Reach (This creature can block creatures with flying.)
Landfall — Whenever a land you control enters, create a 1/1 green Elf Warrior creature token.

Forest

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land you control enters, you gain 1 life.

Emeria Angel

Flying
Landfall — Whenever a land you control enters, you may create a 1/1 white Bird creature token with flying.

Kynaios and Tiro of Meletis

At the beginning of your end step, draw a card. Each player may put a land card from their hand onto the battlefield, then each opponent who didn't draws a card.

Mountain

Grazing Gladehart

Landfall — Whenever a land you control enters, you may gain 2 life.

Greensleeves, Maro-Sorcerer

Protection from planeswalkers and from Wizards
Greensleeves, Maro-Sorcerer's power and toughness are each equal to the number of lands you control.
Landfall — Whenever a land you control enters, create a 3/3 green Badger creature token.

Arcane Signet

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

Command Tower

Glyph Elemental

Bestow {1}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on Glyph Elemental.
Enchanted creature gets +1/+1 for each +1/+1 counter on Glyph Elemental.

Adventuring Gear

Landfall — Whenever a land you control enters, equipped creature gets +2/+2 until end of turn.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)