Janus Thickey was a British wizard. In 1973, he faked his own death by pretending that a Lethifold had eaten him. He scribbled a note on his beside table that read "oh no a Lethifold's got me I'm suffocating," and his wife and children were so convinced by it, and the fact that his bed was still neatly made, that they entered a period of mourning.
The Janus Thickey Ward at St Mungo's Hospital for Magical Maladies and Injuries is presumably named after him.
The name "Janus" means "archway" in Latin. Janus was the Roman god of gateways and beginnings, often depicted as having two faces looking in opposite directions. The month of January is named for him.