Rumor Gatherer

Alliance — Whenever another creature you control enters, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Sigil Captain

Whenever a creature you control enters, if that creature is 1/1, put two +1/+1 counters on it.

Trostani, Selesnya's Voice

Whenever another creature you control enters, you gain life equal to that creature's toughness.
{1}{G}{W}, {T}: Populate. (Create a token that's a copy of a creature token you control.)

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Tribute to the World Tree

Whenever a creature you control enters, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

Sylvan Anthem

Green creatures you control get +1/+1.
Whenever a green creature you control enters, scry 1.

Angelic Chorus

Whenever a creature you control enters, you gain life equal to its toughness.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Surrak and Goreclaw

Trample
Other creatures you control have trample.
Whenever another nontoken creature you control enters, put a +1/+1 counter on it. It gains haste until end of turn.

Railway Brawler

Reach, trample
Whenever another creature you control enters, put X +1/+1 counters on it, where X is its power.
Plot {3}{G} (You may pay {3}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Temple of Cultivation

(Transforms from Ojer Kaslem, Deepest Growth.)
{T}: Add {G}.
{2}{G}, {T}: Transform Temple of Cultivation. Activate only if you control ten or more permanents and only as a sorcery.

Ojer Kaslem, Deepest Growth

Trample
Whenever Ojer Kaslem deals combat damage to a player, reveal that many cards from the top of your library. You may put a creature card and/or a land card from among them onto the battlefield. Put the rest on the bottom in a random order.
When Ojer Kaslem dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Kaslem, Deepest Growth // Temple of Cultivation

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Selvala, Heart of the Wilds

Whenever another creature enters, its controller may draw a card if its power is greater than each other creature's power.
{G}, {T}: Add X mana in any combination of colors, where X is the greatest power among creatures you control.

Verdant Sun's Avatar

Whenever Verdant Sun's Avatar or another creature you control enters, you gain life equal to that creature's toughness.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.

Good-Fortune Unicorn

Whenever another creature you control enters, put a +1/+1 counter on that creature.

Selvala, Eager Trailblazer

Vigilance
Whenever you cast a creature spell, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
{T}: Choose a color. Add one mana of that color for each different power among creatures you control.