Guillermo del Toro recently tried to get a third Hellboy made and spoke with Hellboy creator Mike Mignola and star Ron Perlman about the possibilities of actually getting it made!
Unfortunately its not to be with Del Toro taking to twitter to confirm the bad news,
“Hellboy 3 Sorry to report: Spoke w all parties. Must report that 100% the sequel will not happen. And that is to be the final thing about it”Hopefully it can happen in some form be it comic, animation or radio play!