Perlman told IGN that he is going to push Guillermo del Toro to do it.
"[Del Toro and I] both walked away from 'Hellboy 2' agreeing that there would never be another one. But, with the passage of time, it became clear to me that he really always designed it as a trilogy.
[Guillermo] has a very well-articulated idea of what the resolve would look like and it's amazingly theatrical and is epic in scope and would make for amazing cinema, with or without the first two movies. I said [to Guillermo], 'You owe it to the world to finish this trilogy'. I've been giving him Jewish guilt."