Llanowar Stalker

Whenever another creature you control enters, this creature gets +1/+0 until end of turn.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Borderland Explorer

When this creature enters, each player may discard a card. Each player who discarded a card this way may search their library for a basic land card, reveal it, put it into their hand, then shuffle.

Adventurous Impulse

Look at the top three cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Tapping at the Window

Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest into your graveyard.
Flashback {2}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Nettle Sentinel

This creature doesn't untap during your untap step.
Whenever you cast a green spell, you may untap this creature.

Scythe Tiger

Shroud (This creature can't be the target of spells or abilities.)
When this creature enters, sacrifice it unless you sacrifice a land.

Experiment One

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Remove two +1/+1 counters from this creature: Regenerate it. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Rogue Elephant

When this creature enters, sacrifice it unless you sacrifice a Forest.

Harvest Wurm

When this creature enters, sacrifice it unless you return a basic land card from your graveyard to your hand.