"Big One" is the name of a 4-8-8-4 "Big Boy" belonging to the Sirius Platoon, stationed on the Galaxy Railways. He is one of the main protagonists in the "Kitty Katswell's Adventures" series, occasionally helping the Wubb Girlz on their adventures too. His first adventure with them was in Kitsandra Katswell's Adventures of Sleeping Beauty, in which he helped the group defeat Maleficent and break her curse placed on the Princess Aurora.
Big One is based on a Union Pacific "Big Boy", one of the largest steam locomotives in America. In the series "The Galaxy Railways" and also "Kitsandra Katswell's Adventures of Sleeping Beauty", Big One is seen hauling nine passenger coaches and one rail-cannon.
Big One is an older engine, meaning he's a wise, yet sometimes spunky big engine. He's got a heart of gold and will always be there to help his comrades no matter how dire the situation is. He cares for Yuki Sexaroid like she was his daughter and doesn't give up on her either. At one time though, he was self-concious about not being an equal member of the Sirius Platoon. He believed that since there were no tracks to follow, then there wa no destination for him, and he should sleep peacefully in the well with his brothers and sisters. After hearing encouragement from Manabu, Louise, Captain Bulge, and everyone else, Big One realizes he is a member of Sirius Platoon as well, and that they never give up. So he couples all the engines of the missing trains together, and they all are powerful enough to make it out of the well. The couplers break on the other engines however, and they float back to the well to sleep in peace.
Prototypical to the "Big Boy", Big One is painted a dull-grey color with a white smokebox and. He also has white numbering on his cab and tender that read: "001". His number plate is seen on his firebox door and it has "G8001" on it. When he's rebuilt with a streamlined front though, the numberplate turns red with gold lettering.
- "The Galaxy Railways" - Himself
- "Kitsandra Katswell's Adventures of Sleeping Beauty" - Himself
- "Kitsandra Katswell's Adventures of the Galaxy Railways" - Himself
- "Kitsandra Katswell's Adventures Aboard the Galaxy Express 999" - Himself
- "Sleeping Dannirella" - Himself (does not speak)