Simian Spirit Guide

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Kari Zev, Skyship Raider

First strike, menace
Whenever Kari Zev, Skyship Raider attacks, create Ragavan, a legendary 2/1 red Monkey creature token. Ragavan enters the battlefield tapped and attacking. Exile that token at end of combat.

Kird Ape

Kird Ape gets +1/+2 as long as you control a Forest.

Treetop Village

Treetop Village enters the battlefield tapped.
{T}: Add {G}.
{1}{G}: Treetop Village becomes a 3/3 green Ape creature with trample until end of turn. It's still a land. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Experiment One

Evolve (Whenever a creature enters the battlefield under your control, 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 Experiment One: Regenerate Experiment One. (The next time this creature would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

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.

Mountain

Become Immense

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target creature gets +6/+6 until end of turn.

Bequeathal

Enchant creature
When enchanted creature dies, you draw two cards.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Gorilla Titan

Trample
Gorilla Titan gets +4/+4 as long as there are no cards in your graveyard.

Forest

Hooting Mandrills

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Trample