For non-WoW players, this is not unlike RFL. Dravvie, who probably should be sainted by now, started with her guild raising money for a vaccine against Triple Negative Breast Cancer, via the Cleveland Clinic, and was so successful that it is now an official 'mini-holiday' in World of Warcraft.
People create Level 1 Gnome characters and run from their starting zone down to the end of the continent, facing a crashing server, sharded instances, and - in the south - wolves and hostile Troll and Goblin NPCs! (That part's not like Relay for Life at all.) At the end, everybody jumps in the bay and forms a big heart for the cameras.
TIME FOR THE RUNNING OF THE GNOMES!