King Nebuchadnezzar II was one of the kings during the Babylonian empire. He was noted for conquering one of the greatest djinn of the ancient world, King Solomon. However he was unpopular because after he did so, Nebuchadnezzar destroyed Jeruselam and stole the Solomon's Grimoire. King Nebuchadnezzar built the Ishtar Gate in Babylon in the honor of the first Blue Djinn, but in his self-pride he also built himself a magnificant palace. This angered the Blue Djinn because he built himself a greater palace than her own.
As a punishment, he is forced to stay in the Iravotum and has been there for millennia. He only survives because he, literally, has nothing to be desired. In John's travels in the Iravotum to rescue his sister, he meets him. he also thinks grass is reguler food