- Complete Monster: Erzsebet Ondrushko from Blood and Iron is an evil countess based on the infamous Elizabeth Bathory. Consumed by her vanity and wishing to stay young and beautiful forever, Ondrushko sold her soul to Hecate, the Greek Goddess of Witches. In exchange for her soul, Hecate transforms Ondrushko into a vampire and gave her the power to rejuvenate her body if she bathes in the blood of young women. Ondrushko is said to have murdered over a thousand people in her quest to remain young. Through a series of flashbacks, we see Ondrushko take over a dress shop (by murdering the shop owner and her infant child) to lure in and kidnap a young girl named Anna. Anna's fiance gathers a rescue party, including a young Professor Bruttenholm, to rescue her. They go to Ondrushko's castle, which is filled with torture devices and the bodies of young women and find Anna drained of blood, and so they kill her to prevent her from becoming a vampire as well. Ondrushko kills most of the rescue party, but Bruttenholm manages to kill her. Though her body died, her evil spirit remained. Sixty years later, the BPRD is sent to investigate a supposed haunted mansion, which is in fact haunted by the souls of Ondrushko's many victims. Ondrushko's minions resurrect her and she bathes in the blood in the mansion's owner to rejuvenate herself.
- Heartwarming Moments: Pretty much any scene between Hellboy and Professor Bruttenholm in Blood and Iron. The father/son bond between the two of them is clear as day.
Professor Bruttenholm: (fondly) You grew so fast, at first. In no time at all, you were too big to spank.Hellboy: (smirks) Only 'cause the tail got in the way.
- Nightmare Fuel:
- To anyone with arachnophobia, the scene where HB encounters the Jorōgumo in Sword of Storms. So. Many. SPIDERS! *shudder*
- Values Dissonance - Many Western viewers don't understand why the Samurai's actions in Sword of Storms shamed his Daimyo. A brave hero who rescues a fair maiden from evil demons and spares his liege lord the horrible choice between sacrifice and destruction is the foundation of European Legends and Fairy Tales and usually earns a reward of the maid's hand in marriage or a lordship of his own, not being turned into a statue and his love murdered by her father.
- What Do You Mean, It's Not for Kids?: The animated films are in no way child-friendly, and in some ways are Darker and Edgier than even the live-action films.