I've seen multiple references to Nimmersatt in the recent updates however does an NPC named Nimmersatt exist and is there any additional lore about him?
References To Nimmersatt
Nimmersatt's Lair is on Banor's Eye where the new raid for the Dragon Slayer Outfit item takes place.
Nimmersatt's Breeding Ground is the new dragon spawn in Zao.
Nimmersatt's Seal can be looted from the dragons at the breeding ground.
Additional details
The Dracoon tells us that he is a dragon.
Nimmersatt trapped The Dracoon and kept him as his cook for 20 years.
We meet Nimmersatt's master cook- The Fryclops
Nimmersatt's created the Titano Dragon at his hidden base.