Filming has begun for the Hellboy sequel, which will have a score by Danny Elfman and 30 monsters.

Principal photography has begun in Budapest, Hungary, on the action-thriller Hellboy 2: The Golden Army, the sequel to 2004’s Hellboy from writer/director Guillermo del Toro, scheduled to hit theaters on August 1, 2008.

Del Toro announced this week that Danny Elfman would score the sequel, taking over for Marco Beltrami who scored the first movie. The director also said there would be around 30 monsters in H2 (compared to 8 in the original), and it will be around a 50-50 CGI to prosthetics ratio.

Returning to the franchise is Ron Perlman in the title role with Selma Blair, John Hurt, Jeffrey Tambor, Brian Steele, and Doug Jones, the latter who also appeared in del Toro’s Oscar-winning film Pan’s Labryinth and will next be seen as the Silver Surfer in this weekend’s Fantastic Four: Rise of the Silver Surfer. [Check out the feature on Jones in USA Today.]

About Universal Pictures Hellboy 2: The Golden Army
After an ancient truce existing between humankind and the invisible realm of the fantastic is broken, hell on Earth is ready to erupt. A ruthless leader who treads the world above and the one below defies his bloodline and awakens an unstoppable army of creatures. Now, it’s up to the planet’s toughest, roughest superhero to battle the merciless dictator and his marauders. He may be red. He may be horned. He may be misunderstood. But when you need the job done right, it’s time to call in Hellboy (Ron Perlman).

Along with his expanding team in the Bureau for Paranormal Research and Development — pyrokinetic girlfriend Liz (Selma Blair), aquatic empath Abe (Doug Jones) and protoplasmic mystic Johann — the BPRD will travel between the surface strata and the unseen magical one, where creatures of fantasy become corporeal. And Hellboy, a creature of two worlds who’s accepted by neither, must choose between the life he knows and an unknown destiny that beckons him.

The screenplay for Hellboy 2: The Golden Army was written by del Toro, from a screen story by del Toro and Mike Mignola, based upon the Dark Horse comic created by Mignola. The film also features British actor Luke Goss (”Blade II,” “Undead”) as the ruthless leader of the underworld, Prince Nuada, and actress Anna Walton (television’s “Out of Hours,” “Vampire Diary”) as his compassionate sister, Princess Nuala.

The film’s producers are Lawrence Gordon (”Hellboy,” “Lara Croft: Tomb Raider,” “Die Hard”), Lloyd Levin (”Hellboy,” “United 93″), and Mike Richardson (”Hellboy,” “Gone”). H2’s behind-the-scenes team includes Oscar-winning director of photography Guillermo Navarro (”Pan’s Labyrinth,” “Night at the Museum”) production designer Steven Scott (”Hellboy,” “Doom”), costume designer Sammy Sheldon (”V for Vendetta,” “The Hitchhiker’s Guide to the Galaxy”), and editor Bernat Vilaplana (”Pan’s Labyrinth,” “La Monja”). Chris Symes (”Eragon”) is the executive producer of the film, with Mike Mignola serving as co-producer.

Hellboy 2: The Golden Army will film in both Budapest and the United Kingdom, with post-production based in London.