River King

Devouring your enemies body and soul.

An Acquired Taste

You gain proficiency in cook's utensils to assist in sating your newfound hunger.  You gain 30ft swim speed to traverse your new domain.

Starting at 3rd level mouth and tongue go thru the following changes:

Just a lick

Starting at 3rd level your tongue may now grow to massive proportions at will. You gain a natural attack, 5ft range, dealing 1d12 bludgeoning damage.

After three successful hits on an enemy, exposure to your saliva poisons your target. This poison may only affect one enemy at a time. 

Yawning pit

Starting at 5th level you may now unhinge your jaw, using two rounds you may eat a tiny or a restrained small creature whole. During and until the start of your next turn you are restrained as your gluttony overwhelms you. You may use this ability a number of times equal to your CON modifier per long rest. 

 

Tongue Whip

Your tongue has grown in strength and length. As a bonus action you may whip your tongue out as a ranged spell attack, this deals 2d6 slashing damage and has a range of 20ft. If you hit a poisoned enemy with this ability they are stunned until the start of your next turn. Your tongue is now considered magical for the purpose of overcoming resistance. 

You can use this feature a number of times equal to your Strength modifier plus 1 (minimum of once), and you regain all expended uses when you finish a long rest.

Note: successful hits with this feature counts towards your acquired taste poison stacks.

Devouring

Devour

Your hunger has grown immensely, which has forced your jaw and month to evolve in turn. Your mouth now has an extra-dimensional nature to it. As an action you may swallow a large or smaller poisoned creature, a swallowed enemy must make a Constitution saving throw. On a successful save, it takes half as much damage and is immediately regurgitated. On a failed save, they take 6d4 acid damage and you may hold then in your mouth until the start of your next turn. If you kill a creature with this feature you gain its CR as temp HP. Additionally, any creature killed in this way may not be revived, as you have devoured them body and soul. 

Plover's respite

You may also use this feature to swallow a willing creature as a reaction, dealing no damage. Swallowing a friendly creature places them in full cover.

After calculating the damage to enemies, any creature within a River king's mouth is petrified for the duration.

You can use this feature a number of times equal to your Charisma modifier plus 1 (minimum of once), and you regain all expended uses when you finish a long rest.

Abyssal Voyage

You and one willing creature(you must be in your mouth) may travel through the rivers of fate. Your start and endpoint must have enough ambient water to support life and must be a place you have seen at least once before. Your DM may allow you to attempt to travel somewhere not meeting these criteria but at a risk. 

You can use this feature a number of times equal to your Charisma modifier plus 1 (minimum of once), and you regain all expended uses when you finish a long rest.

"Boy, the world's one river, and I'm its king. Ain't no place I ain't been; ain't no place I can't go again."

Thick skin

A River king may simply banish the pain, and decree their own health. As a Reaction, you may gain Temporary HP equal to the damage taken since your last turn. After Gaining Temporary HP from this feature All Temporay HP  will fall off after 1 minute. After combat ends, you may use this feature again to regain half of your Temporary HP as health.

You can use this feature a number of times equal to your Charisma modifier plus 1 (minimum of once), and you regain all expended uses when you finish a long rest.