William Nilsson, is a Swedish internet celebrity known for starring in the Laughing Baby YouTube video as an infant.
He appeared in the episode "Canada on Strike" as one of the internet celebrities waiting for their theoretical payments. After events heat up, he laughs while the other internet celebrities bloodily fight and kill each other. The baby's ultimate fate is not shown. Both Laughing Baby and Jessica Rose are the only survivors of the internet celebrity brawl.
Laughing Baby is animated almost exactly as he is in real life. He wears white teddy-bear pajamas, black shoes, and a blue bib with a small attached trough. He has short brown hair and a circular head. He has no other distinguishing features.