Chuggington (2008)

S3E10 Top Secret Koko

Title: Confidential Koko Plot: During a delivery of unique gear to the safari park, Mtambo confides in Koko about a secret mission. They aim to capture footage of a rare spectacle tonight: a mesmerizing luna dance by bats in response to a special bird song. Dr. Gosling has entrusted Koko with the task of recording this enchanting sound, but she must keep it a secret. The safari park must remain quiet to avoid frightening the bird away, adding an extra layer of urgency to their covert operation.