Llanowar Elves

Thud

As an additional cost to cast this spell, sacrifice a creature.
Thud deals damage equal to the sacrificed creature's power to any target.

Unleash Fury

Double the power of target creature until end of turn.

Life's Legacy

As an additional cost to cast this spell, sacrifice a creature.
Draw cards equal to the sacrificed creature's power.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Genju of the Spires

Enchant Mountain
{2}: Enchanted Mountain becomes a 6/1 red Spirit creature until end of turn. It's still a land.
When enchanted Mountain is put into a graveyard, you may return Genju of the Spires from your graveyard to your hand.

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.

Forest

Manamorphose

Add two mana in any combination of colors.
Draw a card.

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.

Groundswell

Target creature gets +2/+2 until end of turn.
Landfall — If you had a land enter the battlefield under your control this turn, that creature gets +4/+4 until end of turn instead.

Rupture

Sacrifice a creature. Rupture deals damage equal to that creature's power to each creature without flying and each player.

The Skullspore Nexus

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
Whenever one or more nontoken creatures you control die, create a green Fungus Dinosaur creature token with base power and toughness each equal to the total power of those creatures.
{2}, {T}: Double target creature's power until end of turn.

Scale Up

Until end of turn, target creature you control becomes a green Wurm with base power and toughness 6/4.
Overload {4}{G}{G} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mountain

Ilysian Caryatid

{T}: Add one mana of any color. If you control a creature with power 4 or greater, add two mana of any one color instead.

Fatal Frenzy

Until end of turn, target creature you control gains trample and gets +X/+0, where X is its power. Sacrifice it at the beginning of the next end step.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Demonic Ruckus

Enchant creature
Enchanted creature gets +1/+1 and has menace and trample.
When Demonic Ruckus is put into a graveyard from the battlefield, draw a card.
Plot {R} (You may pay {R} 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.)