Palinchron

Flying
When Palinchron enters, untap up to seven lands.
{2}{U}{U}: Return Palinchron to its owner's hand.

Flameshadow Conjuring

Whenever a nontoken creature you control enters, you may pay {R}. If you do, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Cavalier of Gales

Flying
When Cavalier of Gales enters, draw three cards, then put two cards from your hand on top of your library in any order.
When Cavalier of Gales dies, shuffle it into its owner's library, then scry 2.

Cavalier of Flame

{1}{R}: Creatures you control get +1/+0 and gain haste until end of turn.
When Cavalier of Flame enters, discard any number of cards, then draw that many cards.
When Cavalier of Flame dies, it deals X damage to each opponent and each planeswalker they control, where X is the number of land cards in your graveyard.

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.

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.

Omnath, Locus of the Roil

When Omnath, Locus of the Roil enters, it deals damage to any target equal to the number of Elementals you control.
Landfall — Whenever a land you control enters, put a +1/+1 counter on target Elemental you control. If you control eight or more lands, draw a card.

Great Whale

When Great Whale enters, untap up to seven lands.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Cavalier of Thorns

Reach
When Cavalier of Thorns enters, reveal the top five cards of your library. Put a land card from among them onto the battlefield and the rest into your graveyard.
When Cavalier of Thorns dies, you may exile it. If you do, put another target card from your graveyard on top of your library.