Cliff Colossus

Defender. This creature is immune to all status effects except unconscious, which only it can induce upon itself.

Deafening intimidation. The creatures massive size means that its deafening roars will leave you deafened and weakened, rolling disadvantage on all attacks.

Action rock Attack. Rock fists attack: +15 to hit, reach 100 ft., Any number of targets. Hit: 2d20 bludgeoning damage. 

Tree throw Attack. Ranged tree Attack: +15 to hit, range 500 ft., 1 target. Hit: 1d20 piercing damage.

Healing.  As a bonus action, this creature can heal itself, or any allies within 50 feet of it up to 20 points each.

Cliffs call. Performing the cliffs call will mean that any creature of the earth will come to its aid.

By stomping the ground, any creature, on its side or not, will be hit with an earthquake. They must roll a dexterity saving check and get above an 18 (Or 8 if they are an ally) in order to avoid taking the 10d20 bludgeoning damage.

Earth shaker (Costs 1 Actions). Betraying a cliff colossus will be the last mistake your bloodline ever makes.

You are utterly destroyed. When the creature raises its head and bellows into the sky it can clear all clouds and could break the atmosphere's shell. So when it yells in its mighty rage, the last sound you'll hear, the sound shreds every last piece of your existence. Your flesh, your bones, your mind and your soul are gone, the only trace a 70-foot wide crater where you once stood and found the unfortune of crossing the Cliff Colossus.

The bellow of the mountain (Costs 1Actions). Deals 100d100 force damage. This will kill you. It will. Don't even try. No helping yourself without at least a teleport action. It leaves no remnant of you. However, the creature will only use this as a last resort for it will also destroy the Colossus' insides.