Summit Apes

As long as you control a Mountain, Summit Apes has menace. (It can't be blocked except by two or more creatures.)

Hooting Mandrills

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

Simian Spirit Guide

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

Kird Chieftain

Kird Chieftain gets +1/+1 as long as you control a Forest.
{4}{G}: Target creature gets +2/+2 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Kird Ape

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

Grunn, the Lonely King

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If Grunn, the Lonely King was kicked, it enters the battlefield with five +1/+1 counters on it.
Whenever Grunn attacks alone, double its power and toughness until end of turn.

Gorilla Berserkers

Trample; rampage 2 (Whenever this creature becomes blocked, it gets +2/+2 until end of turn for each creature blocking it beyond the first.)
Gorilla Berserkers can't be blocked except by three or more creatures.

Gorilla Shaman

{X}{X}{1}: Destroy target noncreature artifact with mana value X.

Kogla, the Titan Ape

When Kogla, the Titan Ape enters the battlefield, it fights up to one target creature you don't control.
Whenever Kogla attacks, destroy target artifact or enchantment defending player controls.
{1}{G}: Return target Human you control to its owner's hand. Kogla gains indestructible until end of turn.