1. Director Guillermo del Toro for years considered this film a dream project and had always wanted to cast Ron Perlman in the lead, but could never secure a budget or studio approval. After the massive success of Blade II (2002), del Toro was offered Blade: Trinity (2004) or Hellboy, and though he briefly considered trying to schedule both in, he chose Hellboy.

2. Baby Hellboy, Sammael, Ivan the corpse, Train Driver and Kroenen were all voiced by Guillermo del Toro

3. The studio wanted Vin Diesel to play Hellboy.

4. Ron Perlman broke a rib while filming the subway scenes. He jumped onto a train that was coming towards him at about 45 mph.

5. One of the headstones in the graveyard in Moscow reads “Here Lies Mike Mignola” - the creator of Hellboy.

6. Hellboy’s line to Liz, “I’ll always look this good,” was originally spoken by Guillermo del Toro to his future wife when she took issue with his casual mode of dressing.

7. WILHELM SCREAM: when the Nazi scientist is sucked into the portal.

8. Hellboy was originally going to have cloven hooves for feet, like in the comics, but it was decided that it would be easier and safer for Ron Perlman to perform his stunts with normal, booted feet.

9. The “cover identity” for the BPRD is “Squeaky Clean Up waste management” (seen on the plaque at the front gate as Myers arrives).

10. The motto, depicted in the lobby floor, of the Bureau of Paranormal and Psychic Defence (Defense) is: “In Absentia Luce Tenebrae Vincit”. Meaning, in the absence of light, darkness prevails (or triumphs).

Hellboy 2 trailer: