Octavian is a skinny 18-year-old youth with blond hair, crazed blue eyes, and skin as pale as Nico's. Octavian wears a white toga over a blue shirt and jeans. It is also mentioned that Octavian reminded Percy of someone, which means he could most likely be referring to Luke Castellan. He often has a ceremonial knife and stuffed animal on hand. His tattoo is composed of a lyre, the symbol of his ancestor Apollo, with SPQR inscribed above seven lines which represents seven years meaning that he has been attending Camp Jupiter since he was 11.

When he appointed himself Pontifex Maximus in The Blood of Olympus, Octavian donned Imperial Gold armor and jewelry, along with flowing purple robes. According to Nico, Octavian looks like a watered-down, unhealthy version of Will Solace – like a photo that had been copied too many times, without anything in him that makes a child of Apollo special.