Spanner has blond hair and is almost always seen wearing a green one-piece jumpsuit and black boots. He was an engineer in the Millefiore's Tech Department at the Merone Base and was a B-Rank Officer of the Black Spell. As one of the Millefiore's genius mechanics, he was responsible for the creation of the Family's Mosca units, including the King Mosca and the Mini Mosca (in the anime). Currently, however, Spanner has been recruited into the Vongola Famiglia by Tsuna after the transportation of the Merone Base by the Hyper-Flame Ring Transfer System. Spanner is described as a "relaxed" character who doesn't seem to get as worked up as Shoichi. It's revealed that Spanner and Shoichi go way back and met each other at a Robotics Competition in High School. They were also in the Tech Department together when they were both with the Millefiore. According to the anime, Spanner makes his own lollipops and designed them to improve one's abilities, both mentally and physically which is why he is always eating them.
He's a technophile and loves Japan because of their advancements in robotics. He's also interested in the power of the Vongola, to the point where he doesn't mind betraying his Family to help Tsuna complete the X-Burner. He's also competitive when it comes to mechanical engineering, going as far as challenging Giannini's skills as the current Vongola technician.
" Until we prove we can fix it... That's how this league is. It's a copycat league. If one team can do it, the other team will try to do it a little more effectively. They think they can do it better than any other team. " Terrelle Smith