Novice Inspector

When Novice Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Essence Warden

Whenever another creature enters, you gain 1 life.

Kor Skyfisher

Flying
When Kor Skyfisher enters, return a permanent you control to its owner's hand.

Forest

Eagles of the North

Flying
When Eagles of the North enters, creatures you control get +1/+0 and gain first strike until end of turn.
Plainscycling {1} ({1}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Sprout Swarm

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Create a 1/1 green Saproling creature token.

Generous Ent

Reach
When Generous Ent enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
Forestcycling {1} ({1}, Discard this card: Search your library for a Forest card, reveal it, put it into your hand, then shuffle.)

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Thraben Charm

Choose one —
• Thraben Charm deals damage equal to twice the number of creatures you control to target creature.
• Destroy target enchantment.
• Exile any number of target players' graveyards.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Elvish Visionary

When Elvish Visionary enters, draw a card.

Plains

Radiant Grove

({T}: Add {G} or {W}.)
Radiant Grove enters tapped.

Spidersilk Armor

Creatures you control get +0/+1 and have reach. (They can block creatures with flying.)

Journey to Nowhere

When Journey to Nowhere enters, exile target creature.
When Journey to Nowhere leaves the battlefield, return the exiled card to the battlefield under its owner's control.