Elder Elemental (Zaratan)

Disclaimer: This subclass is not properly balanced and as such is probably far too powerful or weak. Also, I'm not good at this so you will have to keep track of the features yourself.

The zaratani are powerful beings dwelling in the Elemental Plane of Earth that also often cross over to the material plane as moving mountains that can even be lived on by people. The zaratani are great, mighty beings that live for millennia yet haven't realised that many warlocks exploit them during their near immeasurable lifespan.  Being rather dim-witted creatures, the zaratani are quite easily exploited by prospective warlocks that desire power over the earth itself. A warlock with power from a zaratan is often a rather passive being when undisturbed yet when provoked are engines of absolute destruction much like their patrons. 

 

Bonus Cantrips

You gain access to the magic stone and mold earth cantrips.

Boulder body

If you move at least 15 feet towards an enemy you can ram your body into the enemy (this is an unarmed attack) for 2d8 bludgeoning damage at no extra movement cost if the first 15 feet of movement does not reach the enemy. This enemy must then succeed on a strength saving throw (DC 15) or be knocked prone.

Burrow speed

You gain a burrowing speed equal to your walking speed. This is useable at any time, including with heavy armour.

Tremor sense

While using your burrowing speed you have a 30-foot tremor sense.

Mountain's endurance

At 6th level onwards you can't be magically compelled to move in any way, you become immune to the poisoned condition and are also immune to poison damage

Just a rock...

At 6th level, when you are not in motion you are indistinguishable from a rock by the casual observer or a hostile creature trying to find you. All stealth checks you make are made with advantage even if you are wearing heavy armour and any perception or investigation checks to find you are made with disadvantage.

Spew debris

At 10th level, your digestive tract changes and all food you eat becomes rocks inside of your body. You can spend an action to violently excrete this debris at a single creature as a ranged attack (20/60) dealing 4d10 bludgeoning damage. On a hit, the debris also shatters and creatures within a 10-foot cube of the target (including the target) must make a dexterity saving throw. On a failure, those creatures take 4d10 bludgeoning damage. If any creature fails the save by 5 or more the creature is knocked prone.

Rocky shield

Your patron's immense power causes your unarmoured AC to become 10 plus your constitution modifier plus your charisma modifier. This can be used with a shield.

Higher

You can grow yourself to double your size for 2 minutes once per short rest. If you have the powerful build trait you are classed as large size for this feature. With this trait, you can deal an extra 2d8 bludgeoning damage with any melee attacks (including melee spell attacks) and you can use a reaction to reduce the damage you take by 2d8 a number of times equal to your warlock level per long rest. All melee attacks you make gain an extra 5 feet of range.

Hardened Physique

At 14th level, you gain permanent resistance to bludgeoning, piercing and slashing damage.