8 Video Game Secrets That ONLY Appear On Xmas Day

8. Batman: Arkham City - Calendar Man Christmas

If there's one thing scarier than crime, it's a crime that's on time. Say hello to Julian Day AKA The Calender Man from Batman's Rogue Gallery. This date-obsessed death dealer might not look like much, but he's caused more than a few problems for Gotham's regulars by concocting bizarre plots that take place on specific National Holidays.

Basically, if you're celebrating anything in Gotham, there's a chance he might turn up and ruin the fun. You can actually find Day whiling away his own within Arkham City, and as a lovely little Easter Egg, the devs decided to have jail-bird Jules sing you specific blues depending on the date of your console or PC internal clock.

However, while the concept of this Easter Egg is fun, the actual story is pretty harrowing! Calendar Man tells Bats about how he strangled a street corner Santa, then used the man's suit to sneak into an Xmas party so that he could wrap lights around a Judge's neck and hang him from his own house display. Woof.

Definitely one for the naughty list.