The King has a large, globe-like body mass which is suspended in the air with chains. He has a skull for a head, which is recessed within a larger, outer skull-like formation. He has four arms which hang from his body, each with only three claws on each of his "hands."
In the anime, his appearance is different. His head is still a skull, but it is made of gold. He also wears a gold crown adorned with diamonds, emeralds, sapphires and rubies. He has two large diamonds in the sockets of his skull-like head substituting for eyes. He wears a lot of gold and silver jewelry that are studded with precious stones.
He is regarded as a sort of father figure by all "lesser" Shinigami, and is said to be almost immortal. Many Shinigami refer to him as the "Old Man," and Death Note 13: How to Read says that he "must be very old" because of this.
One of the eyecatch rules given in the series states that extra Death Notes found by Shinigami are generally expected to be returned to the Shinigami King, though this is clearly a rule that Shinigami are not forced to obey. Likewise, lost notebooks must also be reported to the King. Very little information is given about the character itself, aside from Rem's assertion that the King is not easy to trick, an achievement which Ryuk accomplished successfully. On the other hand, he is quite easily bribed, as Midora was able to trade thirteen apples for a second Death Note. Ryuk once referred to him as "that old fart," implying that there are Shinigami who don't like him all that much despite his high status. On another occasion, however, Ryuk seemed worried about "the old man back home" being mad at him and Rem when, under Light's orders, he was going to write fake rules in the back cover of Light's Death Note. This hints that while Ryuk may not like him, he does fear him.
The Shinigami King doesn't seem particularly close or understanding of Ryuk as he stated that he couldn't picture Ryuk dropping his Death Note in the human realm as he considered it "boring," nor did he understand why Ryuk would be carrying two Death Notes.
Though he is only referred to in the third-person and is never seen in the main series, the Shinigami King rules and governs all Shinigami. He also controls all "distribution" of each and every Death Note given to all Shinigami upon their "creation." It is unknown from the manga whether or not he creates Death Notes or just has a certain supply of them, as he is unwilling to replace lost ones. It is also not known whether the Shinigami King actually enforces all the various rules of the Shinigami Realm.
Takeshi Obata once stated that he felt too afraid to design the Shinigami King; he said that he did, however, consider placing the Shinigami King on the book spine for Volume 12. He decided against it, as he felt that the spine would not have enough space to depict him.
- The last volume (volume 13) of the limited-edition anime DVDs included a figurine of the Shinigami King, but this currently only applies to the Japanese version, and volume 9 of the Australian DVD release.
- Only the Shinigami King's Death Note can kill the same human over and over again.