Keyword: Landfall

At the beginning of combat on your turn, up to one target land you control becomes an X/X Elemental creature with trample and haste until end of turn, where X is Obuun’s power. It’s still a land.
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on target creature.

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land enters the battlefield under your control, if it’s your main phase, there’s an additional combat phase after this phase. At the beginning of that combat, untap all creatures you control.

Landfall — Whenever a land enters the battlefield under your control, exile the top card of your library. You may play that card for as long as it remains exiled.
At the beginning of your end step, if there are cards exiled with Valakut Exploration, put them into their owner’s graveyard, then Valakut Exploration deals that much damage to each opponent.

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

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

First strike
Landfall — Whenever a land enters the battlefield under your control, goad each creature target player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

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

Trample
Landfall — Whenever a land enters the battlefield under your control, Skyclave Geopede gets +2/+2 until end of turn.

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

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

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.

Landfall — Whenever a land enters the battlefield under your control, create a 1/1 green Saproling creature token.

When Skyclave Pick-Axe enters the battlefield, attach it to target creature you control.
Landfall — Whenever a land enters the battlefield under your control, equipped creature gets +2/+2 until end of turn.
Equip

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Trample
Landfall — Whenever a land enters the battlefield under your control, Skyclave Geopede gets +2/+2 until end of turn.

Trample
Landfall — Whenever a land enters the battlefield under your control, put a +1/+1 counter on Territorial Scythecat.

When Omnath, Locus of Creation enters the battlefield, draw a card.
Landfall — Whenever a land enters the battlefield under your control, you gain 4 life if this is the first time this ability has resolved this turn. If it’s the second time, add . If it’s the third time, Omnath deals 4 damage to each opponent and each planeswalker you don’t control.

Defender
Landfall — Whenever a land enters the battlefield under your control, Skyclave Squid can attack this turn as though it didn’t have defender.

Landfall — Whenever a land enters the battlefield under your control, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

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.

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

Landfall — Whenever a land enters the battlefield under your control, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

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

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land enters the battlefield under your control, if it’s your main phase, there’s an additional combat phase after this phase. At the beginning of that combat, untap all creatures you control.

Landfall — Whenever a land enters the battlefield under your control, exile the top card of your library. You may play that card for as long as it remains exiled.
At the beginning of your end step, if there are cards exiled with Valakut Exploration, put them into their owner’s graveyard, then Valakut Exploration deals that much damage to each opponent.