Ryokugyu is the alias of an admiral in the Marines. His real name is currently unknown. Ryokugyu’s full appearance is unknown, but he has long, wavy hair and wears a Marine coat. He appears to be much taller than Fujitora, who is himself very tall.

Not much is known about Ryokugyu’s abilities, but as a Marine Admiral, Ryokugyu must have at least above-average leadership and coordination skills, and has power over thousands of lower ranked Marines. He has claimed to not have eaten in three years, an impossible feat for a human to do, and he still has the strength to move around and presumably fight.Ryokugyu is a laid back guy, who sun baths outside and doesn’t listen to orders if it brings him discomfort. He also knows Vegapunk and calls him “old”, age is something that he thinks is relevant to mention.

Ryokugyu is called a “beast” by Doflamingo in terms of “power”, but we still don’t know what his Devil Fruit is. I think he owns the mythical zoan “Cernunnos”. Cernunnos is the god of vegetation and doesn’t require eating food, he is a life giver and not taker.

He is sunbathing because that is what Cernunnos does and as the god of fertility he is interested in doing the deed. Ryokugyu can probably control his own vigor/age because his devil fruit is sort of “life itself” and therefore he notices “age” as a weakness in others.

You might know about another person is inspired by Cernunnos, it’s old Bobby B./Robert Baratheon.

The house of Baratheon is based on the celtic god “Cernunnos” and they have a stag as their sigil. Their personalities and will are very similar. All the traits that Ryokugyu has shown are present in Robert’s behavior. His fertility and fighting are the most important things to him and his will is unbreakable. When he doesn’t get what he wants his rage can take out a dynasty. Once someone denies Ryokugyu what he wants, the raging beast will be shown, and we understand why his nickname is so fitting.