While it’s doubtful most people know the origins of the Friday the 13th legend — guilty — there’s no denying the fact that when a Friday falls on the 13th, there’s the slightest sense of dread in the air, as if people are expecting something unfortunate to occur. Over at Twitter, the worldwide trending topics reflect the playful popularity of the day with both “Friday13th” and “viernes13″ appearing.

For those who aren’t sure, Viernes 13 is the Spanish version of Friday the 13th. The top tweets for the English version do a nice job of keeping the spirit of the day alive quite well:

The @Lord_Voldemort7 tweet, linking to a TwitPic post, is just fantastic as it mashes up two icons, Jason Voorhees and Rebecca Black. Incidentally, the @Lord_Voldemort7 account has absolutely nothing to do with Harry Potter franchise. It’s actually a blogger who goes by LV7, and yet, the Twitter account has over 1 million followers. Tweets from this account often show up as a “Top Tweet.” As for what all this means, well, that’s anyone’s guess. Popularity is a fickle beast.

As an example, an account for someone masquerading as Jason Voorhees, which also appears as a “who to follow” account when searching for the “Friday13th” trending term, only has 104 followers. Perhaps being more prolific with such a potentially valuable account is a better strategy. Twitter popularity aside, here’s the image referred to in the above paragraph. It captures the mood of the day quite well:

What kind of Friday the 13th celebration is complete without the infamous theme music appearing somewhere? Not one:

If you’re concerned about how the true legend of Friday the 13th started, start with Wikipedia and work outward.