Tumblr Friends
A group of friends through the website tumblr, with similar interests in either Lord of the Rings, Harry Potter, Boondocks Saints, or other cult movies, music, or celebrities. Known to troll, be forever alone, and accept all challenges, a tumblr friend rides a mighty unicorn into battle, with inside jokes and yelling FUCK YEA.

Also, someone who talks to you to make sure your OK, and looks at the worlds problems, because they are friends with people around the world.
Andy and Liz are tumblr friends, all they ever do is reblog pictures of unicorns from each other.