Koko is a fearless female streamlined Eurostar-type passenger engine built for high speed. Unlike the other engines, Koko is completely electric and draws her power directly from the tracks beneath her. Koko loves going flat out, whooshing ahead of the others, and has yet to learn that speed isn't everything. She loves to explore and have adventures. Koko is very confident and loves to challenge her friends to a dare or race. Although her spirit might get her into mischief, she is always well-meaning and knows when to apologise. Her favourite catchphrases are "Can't catch Koko!" and "Chugga chugga CHOO CHOO!"