Dragon is Jane's best friend. He enjoys toilet humour, burning things, teasing Jane and her friends, lazing about the castle, and having adventures.
Despite being a few centuries old, Dragon has a very childlike and innocent personality, and is extremely friendly. However, he can be very protective and quick to anger if he thinks his friends, especially Jane, are threatened. Dragon is also very sensitive, being visibly hurt when Jane offends or upsets him.
Dragon is known to be a very talented singer, possessing a splendid falsetto voice, though he does not like admitting it. Dragon's scales often cause him great itching, which has been referenced several times in the series. Short-life weapons cannot pierce Dragon's skin, but in "Tests and Jests", Dragon is sensitive enough that Jane can tickle him. He is also very attracted to cows, and finds their general shape and behaviour amusing, especially their mooing.