Rollo is the son of Donna and Logan. He has an adopted older brother, Yip, a twin brother named Lello, and is the older brother of a baby sister, Luca. He is good friends with Yip and Lello, and appears to good friends with Nekoette~Tan, the daughter of Kawaii~Chan and Dante.
In Episode 26 of Season Two, it is hinted that Rollo and Lello may have inherited lycanthropy (werewolf) genes from their father, as they are seen talking about having ears and a tail when they are older, which may be their interpretation of a werewolf transformation. Whether these genes have also passed onto their sister, Luca, is unknown.
In Episode 49 of S2, Rollo states that he had gotten his wolf form recently, before which makes him "officially older" than Lello.
Rollo has brown hair and brown eyes. Rollo wears a navy blue shirt, a light blue long sleeved undershirt, brown trousers, and black shoes.
Rollo takes a strong interest in The Stranger, whose real name is Aaron, but only Aphmau and Laurence are aware of this. He seems to think of Aaron's enigmatic personality as interesting, and is sometimes seen circled around him, alongside Nekoette and Lello, listening to him.
It seems that he is not as wary about strangers as his brother Lello, who is skeptical about talking to Aphmau when the two first meet, as he does not know who she is, but Rollo does not seem to mind her presence.
Also, when Aphmau first met him, he seemed to be quite playful; he didn't really seem to acknowledge her presence except for telling her that he was hidig-bu the again, he was quite little.
- The name Rollo is of American origin. The meaning of the name Rollo is "famous wolf", and since his father is a werewolf, this name could be considered, to an extent, fitting.
- The most famous Rollo of all was a Norseman who became the first Count of Rouen, what would become the title of Duke of Normandy. "Rollo" itself is a Latin version of the Norse name "Hrolf."
- In Episode 25 of Season 2, it was confirmed that Rollo's friend, Nekoette~Tan, was six years old, and had always wanted an older brother, but all the young boys in Phoenix Drop are younger than her, with the obvious exceptions of Yip, Malachi, Kyle and Levin. This makes it safe to assume that Rollo, and his brother Lello, were either four or five years old. In Season 3, Nekoette is nine, therefore Rollo and Lello are either seven or eight.