Dailey is a tank engine. Her quadruplets are Dawson, Damian, and Dave.
Out of her and her brothers, Dailey is usually the voice of reason and she tries to moderate the arguing between the 4 of them.
Dailey (like her brothers) does not have a real-life basis. She was designed by the Fat Controller.
Dailey is painted bright pink with red lining and red wheel spokes.