Mutagenic Growth

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

Manamorphose

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

Tremble

Each player sacrifices a land of their choice.

Mountain

Scythe Tiger

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

Rift Bolt

Rift Bolt deals 3 damage to any target.
Suspend 1—{R} (Rather than cast this card from your hand, you may pay {R} and exile it with a time counter on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Forest

Llanowar Elves

Simian Spirit Guide

Exile Simian Spirit Guide from your hand: Add {R}.

Rogue Elephant

When Rogue Elephant enters, sacrifice it unless you sacrifice a Forest.