Hastur, known for being part of the Cthulhu mythos but originating as a deity mentioned in a short story by Ambrose Bierce
Hastur, aka The Thing in Yellow, the Golden Shepard, Master of the Slithering Sea, That Bastard, Big Yellow, and many other names that incorporate the word ‘yellow’. It’s kind of his schtick.
Stationed on the moon Charon within the aformentioned slithering sea and served by multitude of Star Spawn servants (essentially small clones of himself), he seeks to conquer Pluto as an important stepping stone to becoming the dominant Great Old One in our Solar System. The ongoing resistance of the Mi-Go and their Ancestor Warriors have been a continual thorn in his side.