The newest antagonist for horror movie fans to believe, The Hook Headed Man was conceived while watching Treasure Island on crack. In the movie, the way he came about is described as "A pirate who fell into radioactive sludge." It would have made him into the superhero "Arrr-man", but that was too close to a copyrighted character from Sesame Street, so this is the next-best thing the writers could come up with.
Many images in this compendium are very uncommon throughout the Internet hence the name. Many of these uncommon images have tongue-in-cheek pee-pants humour, thereby they were banned from the Internet for several decades until fans wanted to revive them. Wikipedians reserved images for encyclopedic uses only, however, oddball images from the UnCommons were allowed for Uncyclopedic websites.
A strict policy involves uploading the appropriate images. The image has to be good enough for viewers to accept. Generic images that humor an audience can be added to the compendium to accomodate Uncyclomediacs.