William also stars in Horrid Henry on TV, in which he stays over at Henry's house and seems to be no trouble, resulting in him winning the Big Cash Prize. Moody Margaret stays at William's house and unmistakably hates it there. His teacher is Miss Battle-Axe. Behaviour Rating 5.
Weepy William sits next to Brainy Brian.
Emma Tate voices him.
William has light brown hair and pale skin.
He wears a purple jumper with a pale green shirt, beige trousers, and light brown shoes.
Weepy William appears to cry all day, and he cries when something bad happened, like when his Halloween is ruined in Horrid Henry Tricks and Treats and when he gets caught by the maths monster in Horrid Henry and the Injection. William is very kind as well and he can be tough when he wants to, as in Horrid Henry so not a girl, William is chosen by Henry to assist him and Ralph in water-ballooning Moody Margaret and Sour Susan.
William's best friend appears to be Anxious Andrew, as they both are much alike, and William is supportive and helpful towards his anxious best friend, calming him down when Andrew is very stressed. He also appears a lot with Greedy Graham and Brainy Brian as well, and William seems to be a member of Brainy Brian’s clever-kids club, showing he is intelligent. William is very good friends with Henry after the episode Horrid Henry Ace reporter. William is a member of the Purple Hand Gang, and as such he is good friends with all the boys.
Similar to Moody Margaret, William only has parents with no mentioned siblings. He happens to be the son of a celebrity news reporter and wishes to follow his dad's legacy and become one himself, and while William clearly has a good relationship with his family, his dad might put pressure on him, as William says he wants his son to be just like him.
- William owns a sock puppet called Socky. In Horrid Henry and the School Uniform, Miss Battle-Axe takes his sock puppet away because she saw Anxious Andrew playing with it, but Socky was later returned to him after the confiscation raid.
- He is the only student who truly cares about Miss Battle-Axe. But this is probably because William likes to think that there is good in everyone.
- In Horrid Henry, Rocking the World, Rude Ralph says he's really good at crying.
- In Horrid Henry's Hiccups, he says the saddest thing he can think of is not enough jam on his toast.
- Although William has many appearances due to his presence in Henry's class throughout the series, his biggest role in an episode is arguably in Horrid Henry on TV, or Horrid Henry, Ace Reporter, which caused Henry to respect William as he was nice and helpful, and they became close friends.