hargon
The end boss in Dragon Quest II. He also appears in Dragon Quest Builders 2 as a major antagonist.
In the HD2D remake of Dragon Quest III's end credits, it is revealed that he may have been a human prior to becoming a monster and was a high priest within the castle of the Dragon Lord's mother. It is implied that he may have aided in the Dragon Lord's upbringing.
See also
- Dragon Quest wiki: http://dragonquest.wikia.com/wiki/Hargon