Mists of Salamira
The slythak race
The sylthak are scaled humanoids with lizard tails that are native to the marshes of Salamira guarding ancient treasures near their nests. Most are taller than the average human and usually more resiliant as well. The two common subraces of the slythak include the dryscales and the dampscales.
Dryscales are created as dragonborn with green draconic ancestry, giving them the poisonous breath weapon and resistance to poison.
Dampscales are also created as dragonborn, but they lack any sort of a draconic ancestry. Instead, they posess the following traits.
Protective scales. Their armor class when not wearing any armor is 13+Dex modifier (instead of 10).
Hold breath. Dampscales possess the ability to hold their breath underwater or otherwise for Con minutes (instead of the humanoid Con modifier minutes).
Alert. Damscales gain proficiency in Perception.