Halloween is one of the biggest holidays in the virtual world. Everyone obsesses over what costume they're going to wear. Land owners create spooky builds, graveyards, haunted mansions.
Why is this? I have no idea, even though I get caught up in the madness every year myself. Here in SL, EVERY day is costume day! After all, our avatars can be anything we choose. What's so special about Halloween?
It doesn't matter. It's fun! And that's what SL is all about. So get that special avatar. Dress up as a wicked witch, a mermaid, a ghost, a zombie. And check out some of the many Halloween-themed events!
Linden Lab's official blog has kindly put together a sampling: https://community.secondlife.com/blogs/entry/2651-a-month-of-haunted-surprises-for-everyone/