The tag alias #51746 filthy -> filth has been approved.
Reason: Both tags have about 1.5k posts and almost all posts overlap.
The wiki page for filth describes how both tags are used. The page for filthy does not exist so I'm led to believe they're used in the same way.
EDIT: The tag alias filthy -> filth (forum #310638) has been approved by @bitWolfy.
Updated by auto moderator