Creeper

This is Creeper. 

He was a Goblin from "The black Cauldron". 

Creeper has a purple Cowl and brown Skirt. 

Creeper was intelligent and fiendish, and was loyal to the Horned King 

and he lived in a Castle where the Horned King and his Henchmen were.

Creeper was forcing Hen Wen to show him, Horned King and his Henchmen a Cauldron in her Vision.