|First Appearance||Season 2 ("The Smurfs Christmas Special")|
William was one of two human children who were featured in the cartoon special "The Smurfs Christmas Special". He and his sister Guinevere were out in the forest riding in a sleigh with their grandfather when they were attacked by a pack of wolves that overturned the sleigh and caused great injury to their grandfather, though he wasn't killed. William and his sister first sought help from the evil wizard Gargamel, who roughly turned them away because they had no money. Then, as they were being surrounded by a pack of wolves in the forest, the Smurfs came along to rescue them and bring them to the Smurf Village, where they were cared for and given presents. William thought that Papa Smurf was Santa Claus due to how his grandfather had described him. When Hefty, Brainy, and Clumsy returned to the village after checking the overturned sleigh, reporting that the children's uncle Edgar has found their grandfather, the Smurfs take them back to the sleigh to wait for their uncle there. However, Gargamel had captured the children and took them to the stranger, who later also took Gargamel with him to a clearing where he started a ritual that would take his captives on "their final journey" to his home. The Smurfs, where they found the place that the stranger had taken them to, counteracted his power by counteracted the stranger's power by singing "Goodness Makes The Badness Go Away", which he tried to fight against by using the full measure of his power, but the unrelenting spirit of the singing was too much for him to handle. After he and his ring of fire faded away, William and his sister were reunited with their grandfather who was in his uncle's sleigh, all right and safe.