Board Thread:Support Requests - Community Management/@comment-166057-20130804174916/@comment-1330470-20130804232822

Wikia won't support upload of exotic filetypes by default: if it's not listed on Special:Upload on your wiki, it won't be allowed.

But if you have a specific need, send it to Special:Contact/general and they'll enable more file types for you. I've had BMP and TGA enabled on my wolfenstein... however there's no guarantee of support for any particular type.