Have

Cloudkin Seer

Flying
When Cloudkin Seer enters, draw a card.

Island

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Open the Gates

Search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Flamekin Harbinger

When Flamekin Harbinger enters, you may search your library for an Elemental card, reveal it, then shuffle and put that card on top.

Wave-Wing Elemental

Flying
Landfall — Whenever a land you control enters, Wave-Wing Elemental gets +2/+2 until end of turn.

Mountain

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Woodborn Behemoth

As long as you control eight or more lands, Woodborn Behemoth gets +4/+4 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Grove Rumbler

Trample
Landfall — Whenever a land you control enters, Grove Rumbler gets +2/+2 until end of turn.

Forest

Phylath, World Sculptor

When Phylath, World Sculptor enters, create a 0/1 green Plant creature token for each basic land you control.
Landfall — Whenever a land you control enters, put four +1/+1 counters on target Plant you control.

Ivy Elemental

Ivy Elemental enters with X +1/+1 counters on it.

Omnath, Locus of Rage

Landfall — Whenever a land you control enters, 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.

Fertilid

Fertilid enters with two +1/+1 counters on it.
{1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

Gruul Turf

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

Gruul Guildgate

This land enters tapped.
{T}: Add {R} or {G}.

Khalni Heart Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on Khalni Heart Expedition.
Remove three quest counters from Khalni Heart Expedition and sacrifice it: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Ior Ruin Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on Ior Ruin Expedition.
Remove three quest counters from Ior Ruin Expedition and sacrifice it: Draw two cards.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Risen Reef

Whenever Risen Reef or another Elemental you control enters, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand.

Zektar Shrine Expedition

Landfall — Whenever a land you control enters, you may put a quest counter on Zektar Shrine Expedition.
Remove three quest counters from Zektar Shrine Expedition and sacrifice it: Create a 7/1 red Elemental creature token with trample and haste. Exile it at the beginning of the next end step.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Avenger of Zendikar

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