The 1988 Internet worm perpetrated by RTM. This is a play on Tolkien (compare elvish, elder days). In the fantasy history of his Middle Earth books, there were dragons powerful enough to lay waste to entire regions; two of these (Scatha and Glaurung) were known as “the Great Worms”. This usage expresses the connotation that the RTM crack was a sort of devastating watershed event in hacker history; certainly it did more to make non-hackers nervous about the Internet than anything before or since.