Have

Valakut Exploration

Landfall — Whenever a land you control enters, 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 this enchantment, put them into their owner's graveyard, then this enchantment deals that much damage to each opponent.

Akoum Hellhound

Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Fearless Fledgling

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

Canyon Jerboa

Landfall — Whenever a land you control enters, creatures you control get +1/+1 until end of turn.

Skyclave Shade

Kicker {2}{B}
This creature can't block.
If this creature was kicked, it enters with two +1/+1 counters on it.
Landfall — Whenever a land you control enters, if this card is in your graveyard and it's your turn, you may cast it from your graveyard this turn.

Canopy Baloth

Territorial Scythecat

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature.

Makindi Ox

Landfall — Whenever a land you control enters, tap target creature an opponent controls.

Skyclave Squid

Defender
Landfall — Whenever a land you control enters, this creature can attack this turn as though it didn't have defender.

Tazri, Stalwart Survivor

Each creature you control has "{T}: Add one mana of any of this creature's colors. Spend this mana only to activate an ability of a creature. Activate only if this creature has another activated ability."
{W}{U}{B}{R}{G}, {T}: Mill five cards. Put all creature cards with activated abilities that aren't mana abilities from among the milled cards into your hand.

Skyclave Geopede

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

Phylath, World Sculptor

When Phylath 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.

Felidar Retreat

Landfall — Whenever a land you control enters, 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.

Kazandu Nectarpot

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

Kazandu Valley

Kazandu Mammoth

Kazandu Mammoth // Kazandu Valley

Omnath, Locus of Creation

When Omnath enters, draw a card.
Landfall — Whenever a land you control enters, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add {R}{G}{W}{U}. If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Prowling Felidar

Vigilance
Landfall — Whenever a land you control enters, put a +1/+1 counter on this creature.

Skyclave Pick-Axe

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

Brushfire Elemental

Haste
This creature can't be blocked by creatures with power 2 or less.
Landfall — Whenever a land you control enters, this creature gets +2/+2 until end of turn.

Lotus Cobra

Landfall — Whenever a land you control enters, add one mana of any color.

Moraug, Fury of Akoum

Each creature you control gets +1/+0 for each time it has attacked this turn.
Landfall — Whenever a land you control enters, 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.

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.

Ruin Crab

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

Dreadwurm

Landfall — Whenever a land you control enters, this creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Spitfire Lagac

Landfall — Whenever a land you control enters, this creature deals 1 damage to each opponent.