From Julianne Hough's 'Crazy Eyes' blunder to Matt Lauer's terrifying Pam Anderson, these are some of the worst celebrity Halloween costume offenses ever committed.
2015 had some truly memorable songs, particularly in pop music. What better way to enjoy them all as the year draws to a close than with a massive mash-up? DJ Earworm (aka Jordan Roseman) has been creating mash-ups of the 25 most popular songs each year since 2007, but this year he's upped the ante by combining 2015's top 50 songs into one mega-track.