Definitely Not Kirby

A single star bleeding through the horrible emptiness of space shines upon you. It fills you with visions of dreamlands and cosmic hunger.

You have never felt so hungry. Within your bowels, a chasm grows that is beyond flesh. This new yearning dwarfs divinity. Some might fear it, but you know that this feeling is older than fear. It is older than everything. And it has blessed you with a seed of the infinite.

Inhale

Beginning at 3rd level, you can consume the essence of creatures around you. 

When you enter your rage, choose a creature you can see within 15 ft. of you. You inhale a fragment of that creature's essence, gaining an otherworldly hat based on the creature's type. This hat grants you special features as seen in the table below:

Beasts and Monstrosities - Fur Hat: You gain a special bonus action natural melee attack. This attack deals slashing damage equal to 1d6 + your Strength modifier.

Constructs and Undead - Rusty Helmet: You gain immunity to the Poisoned, Charmed and Frightened conditions and you do not need to breathe.

Dragons, Elementals and Giants - Horned Hat: Once per turn when you hit with a melee weapon attack, you deal extra damage equal to 1d6 + half your Barbarian level rounded down. The damage is acid, cold, fire, lightning, thunder or poison (your choice).

Fey and Plants - Wreath: As a bonus action, you can teleport up to 20 ft. to a space you can see.

Fiends and Celestials - Mitre: When a creature within 5 ft. of you hits you with an attack, you can use your reaction to deal radiant or necrotic damage (your choice) to them equal to 1d6 + half your Barbarian level rounded down.

Oozes and Aberrations - Goo Goggles: When you hit a creature with a melee attack, you can choose to automatically grapple them (no free hands required). You can only have one creature grappled this way at a time.

Humanoids - Top Hat: When you are targeted with a weapon attack, you can use your reaction to add a bonus to your AC equal to your rage damage modifier against the triggering attack.

This hat can't be targeted or removed and disappears at the end of your rage.

Puffy Jump Mode

At 6th level, you can expand the space within you. Your jump distance is doubled and you no longer need a running start for long jumps or high jumps. 

In addition, you can change your direction mid jump one time. 

Void Gut

Also at 6th level, your body opens itself to the void. You can eat indefinitely with no ill effects, however you gain no special abilities to bite, swallow or digest inanimate objects or things you wouldn't normally be able to do. 

Rock Fall Mode

Beginning at 10th level, when you are in mid-air, you can use your action to increase your density to inhuman levels. You become petrified and plummet (600 ft. per round). If you fall 60 or less before landing, you take no fall damage. If a creature is under you when you fall and you would land on them, they must make a Dexterity saving throw with a DC equal to 8 + your proficiency bonus + your Strength modifier. On a failure, they take bludgeoning damage equal to the fall damage you would normally take and are pushed to an empty square within 5 ft. of you and are knocked prone. If you fall more than 60 ft. you take fall damage based on the total height fallen, minus 60, and the creature you fall upon only takes 60 ft. worth of fall damage.

You gain +4 to your AC and remain petrified until the start of your next turn. While petrified in this manner you cannot take actions, bonus actions or reactions. 

Performing this action counts as an attack for the purpose of maintaining your rage.

Swallow

At 14th level, you can consume more than a creature's essence. As an action, you can choose a creature within 10 ft. of you and attempt to consume it. The creature must make a Dexterity saving through with a DC equal to 8 + your proficiency bonus + your Strength modifier. On a failure, you swallow them and gain the associated benefit of your Inhale ability.

A swallowed creature is blinded and restrained, it has total cover against attacks and other effects outside of you and it takes 4d6 acid damage at the start of each of your turns.

Swallowed creatures can use their action to make a contested Strength (Athletics) check against you to attempt to break free. If they succeed, you spit them out into an empty space within 5 ft. of you. 

If the creature you swallow is 1 size larger than you, your movement speed if halved. If you swallow a creature 2 sizes larger than you, your speed drops to 0. Creatures 3 sizes larger than you or greater automatically succeed on their saving throw.

As a bonus action, you can spit out a swallowed creature.