Copper Dragon Master, Rookie

Dragon Student. The Rookie's bond with its dragon partner (and patron) gives it access to an expanded spell list and a copper dragon wyrmling companion. The dragon partner can cast spells as an action in place of the Rookie (using the Rookie's spellcasting modifiers) or take the Bite action from its stat block if commanded using the Rookie's bonus action. Three times per day, when the dragon partner makes a Bite attack, it can deal additional damage of its type or recover health points (its choice) equal to 1d6+6. It takes the dodge action if not given any commands, and if the Rookie is incapacitated, it will take any action it deems necessary, not just dodge. The Rookie gains a climbing speed of 30 ft.

Dragon Pact. The Rookie and its dragon partner share spell slots (which are recovered after a short rest), but all spells cast by your dragon partner become damage of its respective type. It can cast eldritch blast as a modified breath weapon (see actions). The Rookie concentrates on any spell cast by it or the dragon partner that require concentration. Whenever the dragon partner casts a warlock spell as its action, it gains 4 temporary hit points. 

Dragon Warrior. The Rookie can use its Charisma instead of Dexterity or Strength for its attack and damage rolls when using one-handed weapons. These weapons are considered a spellcasting focus. When it hits with an attack, it deals an additional 3 acid damage with that weapon. It can also add its Charisma bonus to any Intelligence ability check it makes.

Innate Spellcasting. The dragon partner’s innate spellcasting ability is Charisma (spell save DC 14). It can innately cast the following spells:

(at will)- mold earth

(as a ritual)- meld into stone

Spellcasting. The Rookie is a 6th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). The Rookie has following warlock spells prepared:

(at will): eldritch blast, booming blade, mage hand, armor of agathys

at 3rd level (2 slots): absorb elements, hex, shield, dragon's breath, flaming sphere, invisibility, counterspell, fireball, lightning bolt 

Acid Breath (Eldritch Blast). The dragon partner exhales acid in a 40-­foot line that is 10 feet wide. Each creature in that line must make a DC 14 Dexterity saving throw, taking 11 (2d10) acid damage on a failed save, or half as much damage on a successful one.

Shortsword. Melee Weapon Attack: +6 to hit, reach 5 ft., 1 target. Hit: 7 (1d6 + 3) piercing damage + 3 acid damage.

Breath Weapons (Recharge 6). The dragon partner uses one of the following breath weapons:

Acid Breath. The dragon partner exhales acid in an 20-foot line that is 5 feet wide. Each creature in that line must make a DC 14 Dexterity saving throw, taking 18 (4d8) acid damage on a failed save, or half as much damage on a successful one.

Slowing Breath. The dragon partner exhales gas in a 15-foot cone. Each creature in that area must succeed on a DC 14 Constitution saving throw. On a failed save, the creature can't use reactions, its speed is halved, and it can't make more than one attack on its turn. In addition, the creature can use either an action or a bonus action on its turn, but not both. These effects last for 1 minute. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself with a successful save.