Shambling Ghast

When Shambling Ghast dies, choose one —
• Target creature an opponent controls gets -1/-1 until end of turn.
• Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Briar Shield

Enchant creature
Enchanted creature gets +1/+1.
Sacrifice Briar Shield: Enchanted creature gets +3/+3 until end of turn.

Aradara Express

Menace
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Rancor

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

Corrupted Conviction

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Mutagenic Growth

({G/P} can be paid with either {G} or 2 life.)
Target creature gets +2/+2 until end of turn.

Swamp

Drey Keeper

When Drey Keeper enters, create two 1/1 green Squirrel creature tokens.
{3}{B}: Squirrels you control get +1/+0 and gain menace until end of turn.

Might of Old Krosa

Target creature gets +2/+2 until end of turn. If you cast this spell during your main phase, that creature gets +4/+4 until end of turn instead.

Acorn Harvest

Create two 1/1 green Squirrel creature tokens.
Flashback—{1}{G}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chatter of the Squirrel

Create a 1/1 green Squirrel creature token.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)