I decided to make my own Thomas and Friends fan-fiction series. The main characters are:

Sir Topham Hatt
Thomas
Edward
Henry
Gordon
James
Percy
Toby
Duck
Donald
Douglas
Oliver
Emily

A select few coaches are also main characters:

Annie and Clarabel (Thomas' coaches)
Old Slow Coach (who works with Edward)
Henrietta and Victoria (Toby's coaches)
Elsie (Toby's luggage van)
Alice and Mirabel (Duck's autocoaches)
Gary, Michelle, and Nigel (Duck's slip coaches)
Isabel and Dulcie (Oliver's autocoaches)
Adam and Franklin (Emily's anthropomorphized coaches)