A Very Mary-Kate Halloween! See more funny videos and funny pictures at CollegeHumor. Watch the video (above) to see Mary-Kate practice for the scariest day of the year! LOLz. Eyes Wide Shut 2.0? Model Shares INSANE Experience From Halloween Party... WHAT?! Martha Stewart Now Blames CRAIG MELVIN For Her Disastrous Halloween... Pete Davidson & Ex Elsie Hewitt Reunite For Baby's First Halloween... Mass Shooting At Spirit Halloween Store In California Leaves 1 Dead,... Oct 27, 2010 19:30pm PDT Share This Categories Halloween Olsen Twins