D&D 5E Favorite official high level npc

[Shades of Eternity]

my stipulations.
1. cr 11+
2. must be a core race (so no demons, devils, etc).
3. Could have conceivably been a high level adventure.
4. is from an official wotc product.

I'm trying to figure something out.

thanks in advance.

 

[IvyDragons]

manshoon