Americans Hate Tingle: If the reception of the film is already divisive in its native U.S., the reception outside America is even worse, being the most notable case Mexico, partly due to the fact being the home of Guillermo del Toro, the director of the previous two films, which for obvious reasons both him and his films are deeply revered there, and also because the film was defeated in box office by a local Mexican film, (No Manches, Frida 2) something that's rather unusual there. Explanation With some very venerable exceptions, most Mexican films since the end of the golden era of Mexican cinema (1920s to 1960s) rarely were able to compete, much less lead, the local box office against either Hollywood or other foreign films, partly because of either lack of advertising or because most of these films past the 1960s were terrible shlockfests unable to even make an earning, and while the Mexican movie industry has managed to make some good movies in later part of the 1990s, most Mexican films were and are still unable to compete against foreign productions. The fact Cultural Cringe is prevalent in Mexican culture doesn't help.
Author's Saving Throw: Ed Skrein was originally cast as Daimio, causing a massive backlash for casting a white actor in an half-Asian role. Skrein hadn't known Daimio is half-Asian in the comics, and upon finding out he promptly withdrew in favor of Korean actor Daniel Dae Kim who was accepted, (despite not being biracial either). In turn, the casting of Daniel Dae Kim was criticized for not being Japanese. It should be noted that the casting of Irish character Alice Monaghan by African-American actress Sasha Lane did not receive nearly the same amount of backlash.
Big-Lipped Alligator Moment: The Stinger of the film centers around Hellboy getting drunk at Bruttenholm's grave, where is he consoled by the ghost of Lobster Johnson, a vigilante from WWII who only had a minor cameo in a flashback. This was clearly meant to be a Sequel Hook, but the film's disastrous box office performance means that it will never pay off.
Complete Monster: Nimue, the Blood Queen, is a tyrant seeking the death of all humanity to build a new Eden out of the bloody ashes. Betrayed by her own coven and her body hacked apart, Nimue has a changeling named Gruagach reunite her pieces, proceeding to horrifically kill the majority of her old coven and unleash a plague upon London when she's whole again. Nimue eventually kills Gruagach after his use wears out, and after her attempt to seduce Hellboy fails, Nimue spitefully cuts the throat of his father Professor Bruttenholm to drive him into insane rage and allow him to become the beast of the apocalypse, unleashing horrific monsters on the world through his power to horribly butcher all humanity.
Ben Daimio in his Jaguar Spirit form and Hellboy fighting side by side.
HB wielding a flaming sword while riding what appears to be a dragon. Its as cool as it sounds.
One-Scene Wonder: Crossed with Visual Effects of Awesome, during the climax the demons of Hell appear in London and begin tearing it and its' population apart. In the limited screentime they appear, its obvious each one is uniquely designed and looks visually horrifying.
Special Effects Failure: When Hellboy comes to on the floor of the elevator that takes him down to Baba Yaga's realm, his horn stumps can be seen moving on his forehead when they briefly scrape along the floor, revealing them as the glued-on prosthetics they are.
The opening shot of a crow plucking an eye out of a dead mans skull, followed by pus oozing out.
Baba Yaga sealing her deal with Hellboy with a kiss. It is more nauseating than the first example.
Hellboy: How do you have hair on your tongue?
A good part of the climax that features Nimue's giant demons skinning people alive.
Tainted by the Preview: In that many fans were turned off by the first trailer's emphasis on comedy, which many saw as detrimental as it seemed to paint the movie as a Self-Parody rather than a Darker and Edgier reboot. And while the ratio is not too terrible, the amount of dislikes the trailer got on Youtube is noticeable.
Took the Bad Film Seriously: While most critics have bashed the movie as a whole, even those who disliked it have admitted that it's not because of David Harbour, who does his damnedest to save the movie from itself despite the immense pressure of having to follow up Ron Perlman's beloved performance.
Tough Act to Follow: This film was in the unenviable position of following up Hellboy II: The Golden Army, widely considered to be an Even Better Sequel to the already highly-regarded Hellboy (2004). The Golden Army ended on a cliffhanger which was meant to lead into a third Hellboy film, completing the trilogy. When the reboot was announced, the reception was nearly universal in that audiences wanted a conclusion to del Toro's Hellboy story. The fact that Guillermo del Toro and Ron Perlman were both willing and eager to return to the franchise did not do the reboot any favors.