Whenever a godchild outgrows his or her fairy godparents, this flying taxi from taxi world appears. In the case of the fairy godparents not wanting to leave their godchild, the taxi has a magnet which can attract the fairies toward it against their will.
The Fairy Taxi appears twice in "Channel Chasers". The first is during a movie demonstration by Wanda to Timmy, showing him what happened to a little girl who became too old for her godparents. As she became more interested in dating her boyfriend, her fairy godparents packed up and left, with the Fairy Taxi arriving to take them back to Fairy World.
At the end of Channel Chasers, Timmy ages himself up into an adult using the Magic TV Remote, causing him to lose his fairy godparents. This renders Vicky and the remote controls momentarily powerless, but the Fairy Taxi immediately appears to take Cosmo and Wanda away from Timmy. They stall, so the Fairy Taxi activates a magnet which pulls Cosmo and Wanda slowly toward it. Cosmo quickly changes Timmy into a baby, and then into his normal ten year old self. Timmy tosses the remote controls at the taxi cab door, closing it before Cosmo and Wanda can enter it. The taxi driver then sees that Timmy is not really grown up, and leaves them without a fuss.
From inside the taxi cab, the voice of Adam West tells the fairies to buckle up.