The Great Hungerer

You have encountered something in your travels. A curse? An affliction? No this is something else altogether. It has made you stronger, tougher, more in tune with the arcane - but you cannot help but crave. An ancient, unfathomable hunger wells up in you, just below the surface of your thoughts, waiting to taste of the world and everything within.

Tireless Hunger

At 1st level, your patron has infected you with its ravenous appetite and granted you the means to feed it. Your maw becomes a natural weapon, which you can use to make unarmed strikes, and you can use Charisma instead of Strength for the attacks and damage rolls of unarmed strikes made with this weapon. You roll 1d6 piercing damage when you hit with it, instead of the bludgeoning damage normal for an unarmed strike.

If you later gain the Pact of the Flesh feature your maw counts as one of that boon’s natural weapons and your unarmed strikes from that feature can use your Charisma modifier for attack and damage rolls. You must use the same modifier for both rolls.

Eldritch Vitality

Also at 1st level, you gain Proficiency in the Constitution (Eating) skill. You gain a number of temporary Hit Points equal to half your Charisma modifier (rounded down) at the end of each of your turns. This number increases to your full Charisma modifier when you reach 6th level in this class.

Ravenous Strikes

Beginning at 6th level, when you gain temporary hit points at the end of your turn from the Eldritch Vitality feature, the number of temporary hit points you gain is equal to your full Charisma modifier, or you can instead gain temporary hit points equal to half the total damage you have dealt with your unarmed strikes over the course of your turn.

Eternal Hunger

Starting at 10th level, you add your Charisma modifier to your stomach capacity and stuffing rolls.

Additionally, you emanate an aura of hunger in a 10-foot radius. The first time any enemy creature enters the aura or starts its turn there during a battle, the creature takes necrotic damage equal to your Charisma modifier. When you damage an enemy with this feature and you are not full (including the result of an Eating check), your stomach fills with pounds of Fatty food equal to half the damage done to that creature.

The Shape of Hunger

Starting at 14th level, you may use an action to transform into the Shape of Hunger. You immediately digest all food in your stomach, gaining two pounds of fat or muscle for each pound of food you digest in this way (your choice) and regaining a number of Hit Points equal to the number of pounds of food digested. The Shape of Hunger lasts 1 minute, and while transformed you receive the following benefits:

• Your size increases by one category, doubling in all dimensions and multiplying your weight by eight. If there isn’t enough room to double your size, you attain the maximum possible size in the space available.
• You have advantage on Strength checks and Strength saving throws.
• Your unarmed strikes deal an additional 1d4 damage.
• The range of your Eternal Hunger becomes 30 feet, and the amount of food you gain from it is equal to the full damage it deals.
• Immediately after you hit an enemy in range of your Eternal Hunger with an unarmed strike, you can use your reaction to instantly digest all of the food in your stomach. You regain Hit Points equal to the number of pounds of food digested. You also gain two pounds of fat or muscle for each pound of food digested this way. Food digested in this way does not give you diet points.

Once you use this feature, you can’t use it again until you finish a long rest.