Due to spending so long crafting potions and studying tomes, not to mention living inside volcanoes, your clan possesses incredible Wisdom and Constitution. You gain a +1 to Wisdom, and a +2 to Constitution.

Reaching maturity at around 12, Firenewts can live to be almost 70.

Firenewts are taller and slimmer than humans, standing around 6 feet tall and averaging almost 120 pounds. Your size is Medium.

As a Firenewt, you have adapted to swimming in both lava and water. Your speed is 30ft., and you possess a swimming speed equal to your walking speed. You can also swim in lava as if it were water, and have visibility in lava as if it were water.

As a Firenewt, you have been trained in alchemy due to your love for fire. You have proficiency with alchemy supplies, and can cast the Light spell at will. When you cast Light on an object, the object appears to be covered in molten lava.

As a Firenewt, you can breathe lava, air, and water.

Like many adventurous Firenewts, you have learned to master the power of flame, expelling powerful fire from within. As an action, you may send a bolt of fire toward a target you can see within a range of 10 feet times your proficiency bonus. Make a ranged weapon attack, adding your proficiency bonus. On a hit, this bolt bypasses fire resistance, and deals fire damage equal to (your proficiency bonus)d4. 

Having hidden within volcanoes for centuries, you have adapted to lava to a greater extent than even most Firenewts. As such, you are immune to fire damage, and a lava pool is your version of a hot spring. You also possess a swim speed equal to your walking speed in both water and lava. In addition, you can breathe in both water and lava, and benefit from visibility through lava equal to that of water.

Unfortunately, due to this same adaption, you are vulnerable to cold damage. If you go for more than 1 week without bathing in hot water, you have disadvantage on attack rolls and saving throws until you enter hot water once more.

As a Firenewt, your lava-like form emits light. As a bonus action, you may cause yourself to shed dim light in a 5-foot radius indefinitely, or turn off this light. In addition, you may use concentration to shed bright light in a 5-foot radius and dim light for an additional 5 ft., or use an action to increase these radii by 10 ft. for the duration of your turn.