Charlie is a small, playful engine from the Mainland who likes to have a lot of fun. He has a reputation for being a really fun engine. He has an unquenchable desire for fun, games and play, and is said to have been the favourite engine of the Mainland Controller. Charlie can get easily distracted by his japes, sometimes distracting others in the process. Charlie can be pouty, huffy, and teasing at times, but he always wants everyone to be enjoying themselves. Often though, Charlie will learn that the opinions of others, keeping calm and working hard to complete your jobs foremost, are important if you want to be a Really Useful engine. He has a good working relationship with Edward, often calling him "Eddie", who is sometimes capable of taking Charlie under his wing, and Thomas, who Charlie enjoys racing and sharing in the fun with. Being a fun-loving, playful scamp, cheeky Charlie is popular at parties and fairs, is well liked by the children, and known for his youthful humour. Tigger refers to him as "Charlie boy", which Charlie loves that nickname very much.
- Charlie will meet Winnie the Pooh, Twilight Sparkle, Ash Ketchum, SpongeBob and their friends in Pooh's Adventures of Thomas and Friends: CGI TV Series.
- Charlie will make his first appearance in the third series of Thomas and Twilight Sparkle's Adventures Series as part of the team in Thomas and Twilight Sparkle sings Mamma Mia.
- Pinkie Pie, Dodger, Pepper Clark, Genie, Fozzie Bear, and Mako are Charlie's best friends.