While some seek to master the arcane secrets of magic to gain power, others take a more direct approach towards the mystical – consumption. There are creatures with insatiable appetites for the energy source known as magic lurking between the stars, deep in the Underdark, and in demiplanes of void, nightmare, and anti-life. Individuals who offer service to these creatures and their hungers are given abilities to hunt magic sources, as well as the chance to siphon some of these energies for themselves. 

Outsiders such as Hakeashar the Magic Eater, Elders such as Hadar the Dark Hunger,  and Demon Lord Juiblex the Oozing Hunger are all some of the most eager patrons a warlock may find. Powerful mages or even artificers require aid in collecting arcane energy, and are not above turning individuals into magic batteries. A magic-eating patron may not even be sentient: infection by an extraplanar parasite or disease could create a similar effect.

Expanded Spell List

The Insatiable lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Insatiable Expanded Spells

Spell Level	Spells
1st	false life, ray of sickness
2nd	see invisibility, silence
3rd	gaseous form, wind wall
4th	locate creature, black tentacles
5th	wall of force, passwall

Senses of the Ravenous

Your patron grants you the ability to track down strong sources of magic on which to feed. You gain the ability to cast the  Detect Magic spell as a ritual. You can also cast this spell normally with any spell slots you have. Using this ability grants you a range of detect magic up to 120 feet and is not hampered by obstacles such as stone, wood, or steel.

Gluttonous Excess

At 1st level, you are given the ability to siphon magical life energy from those you attack for your patron. You have a pool of two d4s. When you make an attack, you can take some of a creature's magical essence, spending dice from your pool and dealing additional necrotic damage equal to the roll. Additionally,  you gain half of the resulting necrotic damage worth of temporary hit points (minimum of 1). The size of your pool increase as you gain levels in this class: two dice at level 1, four dice at level 6, six dice at level 10, and eight dice at level 14.

Any spent dice are refreshed on a long rest.

Boundless Appetite

As your patron's influence seeps through your body, your senses sharpen when you get a taste of powerful magic. Starting at level 6,  you can add your CHA modifier to a saving throw  made against a creature's spell attack. If you succeed the saving throw, spent dice numbering up to half of your Gluttonous Excess pool of d4s are refreshed, and your next attack roll against the creature has advantage if you make it before the end of your next turn.

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

Devouring Aura

Starting at level 10, you can become a portal to your patron’s hunger, taking energy from creatures around you and drawing sustenance from it.  You do not need to eat or drink, and have advantage on suffering exhaustion.

Additionally, your patron aids you in hunting enemy spellcasters. Immediately after a creature within 30 feet casts a spell that targets you or includes you in its area of effect, you can use your reaction to force the creature to make a Constitution saving throw against your spell save DC. On a failed save, the creature's speed is halved and they suffer disadvantage on attacks while they are within 30 feet of you. This feature can be used once per short or long rest.

Ravaging Phagotrophy

Starting at 14th level, when you hit a creature with an attack, you can use this feature to instantly engulf the target in the ingesting aura of your patron. The target is incapacitated until end of your next turn, and, if the creature can cast spells, the creature loses one random spell of the creature's highest level spell slots and any spent dice in your pool of d4s for Gluttonous Excess are returned. 

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