As an artificial recreation of an ancient giant, Juki is significantly larger than even normal giants. He appears to be hunchbacked, and possesses an elongated head resembling that of a dragon. His mouth is lined with large, sharp teeth, and his tongue often hangs out of the side. His eyelids are notably dark. He has a pair of dark horns that go up at first but then slope downward about a third of the way up. He has a wild mane of light hair that starts out narrow between his horns but shrouds his backside. Like many of his fellow Numbers, Juki's only article of clothing is a loincloth with tiger stripe-like patterns on it.
Like the other Numbers, Juki is frequently drunk and brutishly violent against the Beasts Pirates' enemies. He appears to be quite careless, as he dropped a barrel of alcohol while drinking from it. Like the other Numbers, he has a unique laugh that plays off his name: "Jukikiki".
On the day of the Fire Festival, Juki and the Numbers took part in the Beasts Pirates' Golden Kagura festivities. While drinking, Juki ended up dropping his alcohol barrel, annoying his crewmates nearby. However, the party did not last long as the Ninja-Pirate-Mink-Samurai Alliance invaded Onigashima to take down Kaido. Once the fighting broke out, Juki began rampaging in the Skull Dome with Jaki and Goki. When Goki confronted Monkey D. Luffy, Juki went to assist him, but was then suddenly struck to the ground by X Drake's X Calibur attack.