The Dragon.

Your patron is a dragon, a powerful creature that's been on the planet since time immemorial, while reclusive, they sometimes get sought out for their vast amounts of knowledge or power, but it's very rare that they actually grant these things, unless it's in exchange for something else.

Level 1 Features:

Draconic Magic.

When you learn a spell of the appropriate level using your pact magic feature, you also learn the spells on the Draconic Spells table. The spells count warlock spells for you, and do not count against your spells known.

Dragon Kind.

You choose your patron’s kind and the damage associated with it or determine it randomly, using the Dragon Kind table. If you cast a spell that does either Acid, Cold, Fire, Lightning or Poison damage, you can change it to the damage type associated with the kind of dragon you have made a pact with.

Draconic Form.

Starting at 1st level, your draconic patron bestows upon you a sliver of its draconic essence that you can call forth with your pact magic.
As a bonus action, you can expend one spell slot to enter your draconic form. In your draconic form, your body twists to outwardly reveal your draconic magic and you gain access to your draconic gifts.
Your draconic form lasts for a number of rounds equal to 1 + the level of the spell slot used to call forth your draconic form, after which you can no longer use your draconic gifts until you spend a spell slot to call forth your draconic form again.
Choose one of the following draconic gifts:
-Draconic Wings: Dragon-like wings sprout from your back. You have a flying speed equal to your walking speed.
-Draconic Hide: Scales cover your skin. Your AC is increased by an amount equal to your proficiency bonus.
-Draconic Heart: Your vitality increases to match that of a dragon. You gain temporary HP equal to 1d10 plus your warlock level.
-Draconic Claws: Your fingers sprout sharp claws. You are proficient with your unarmed strikes, they count as magical for the purposes of overcoming resistances, and on a hit you deal slashing damage equal to 1d6 plus your Intelligence or Charisma modifier.
-Draconic Invocation: Your pact magic strengthens while in your draconic form. Choose an Eldritch Invocation you have not yet chosen (you must meet its requirements). You gain the benefits of said Eldritch Invocation while in your draconic form.
-Draconic Eye: You gain blindsight to a distance of 60 feet.
Frightful Presence: You exude an aura of fear. Each hostile creature that starts their turn within 60 feet of you must succeed on a Wisdom saving throw against your spell casting DC or be frightened of you. A creature repeats their saving throw at the end of their turn. A creature that succeeds on this saving throw is immune to your Frightful Presence for 24 hours.
You can choose an additional draconic gift at levels 5, 11, and 17.

Eldritch Breath.

Also at 1st level, you gain an action you can only use while in your draconic form.
As an action, you exhale a 10 foot cone of the damage type associated with your dragon patron. Each creature in that area must make a Dexterity saving throw against your spellcasting DC, taking an amount of damage equal to 1d10 + your charisma modifier + the spell slot level you used to enter your draconic form, or half as much on a successful save.

Level 6 Feature:

Draconic Presence.

At 6th level, your pact with the dragon has given your body a draconic flair.
You are immune to the frightened condition, you can speak Draconic, and you have resistance against the damage type associated with your dragon patron.

Level 10 Feature:

Draconic Protector.

At 10th level, your pact is strong enough for you to call forth the dragon’s endurance as a last resort.
If you fail a saving throw, you can choose to succeed it instead. Once you’ve used this ability, you cannot use it again until you finish a long rest.

Level 14 Feature:

Draconic Essence.

At 14th level, your essence has been irrevocably changed by the influence your patron has over you.
Select one of the draconic gifts you possess through your Draconic Form feature. You now enjoy that draconic gift both in and out of your draconic form.