Age: Probably around eight to ten years.
Full Name: William John Longtail.
History: William is a young grey mouse whom is the best and closest friend of Angelina and Alice's in the first series of the show as well as the books. Other times when he's not hanging out with Angelina or Alice, he's sometimes seen with Henry, which he acts a little bit like an older brother figure or family member to Henry. In most episodes when William is around or talking about Angelina, it is shown that he has a crush on her. Although it's unknown if she returns his feelings he has for her.
Personally: William is a soft spoken boy mouse, who, unlike Angelina, is more of a follower than a leader and has an English accented voice. He, besides Henry, is the only male in Miss Lilly's ballet class, and the only male who has the roles of the prince, guard, or king as Angelina mostly plays the female love interest when needed.
Interests: Ballet, his friends, his father, Angelina.
Dislikes: Sammy and his friends picking on him, Sammy making trouble for him, Angelina not retuning his feelings, seeing Angelina with someone else (possibly), Angelina yelling at him, getting something wrong by mistake.
Fan-Art: There is very little fan-art of William, even just with Angelina.
Fanfictions: There isn't really any fanfictions with William, although, a few authors are planning to write a romacee-drama stroy of William returning and Angelina being stuck in a love tranglee with William and Marco.
Fan-Videos: So far, no fan-videos of William has been made, but YouTuber, CrazyVideos50 has been planning to make a Drama/Romance Fan-Series with a few characters from both, the Show and it's Classic Series as it takes place after the show a few years later when William finally returns but Angelina realises she does returns his feelings after seeing him again for years, but she still likes Marco as well It is unknown if the Fan-Series will be able to happen, due to the act that most voice-roles for the characters might not be enough.
- William was voiced by Keith Wickham, who also voiced Maurice Mousling, Grandpa Jeffrey Mousling and Doctor Tuttle.
- Both Wickham and Uncle Louis' voice actor, Rob Rackstraw, currently voice characters in Thomas And Friends.