In the final days of World War II, the Nazis attempt to use black magic to aid their dying cause. The Allies raid the camp where the ceremony is taking place, but not before a demon—Hellboy—has already been conjured. Joining the Allied forces, Hellboy eventually grows to adulthood, serving the cause of good rather than evil.
This movie contains 41 potentially triggering events.
The character Abe Sapien has little holes on his hands that resemble octopus suction cups. He uses his hands to read people and situations so we do see his hands a few times. The holes aren't too close together, but they could make someone with trypophobia squirm a little.
The villain does not literally sexually assault Liz when he has her captive near the end, but some of his behaviour is suggestive of sexual assault in a way that may be uncomfortable for some viewers. (I'm thinking particularly of the way he invades her personal space when he's stealing her life force.)
For one thing, there's a character who's been extensively mutilated - massively scarred, *no lips or eyelids* - there are only a few shots where he's not wearing clothing that hides his deformities, but they're pretty unpleasant.
A zombie is carried by a noose around his neck: he is not bothered or hurt by this, and it doesnt hurt his flesh or anything because he is mainly just bones
Hellboy could be interpreted as trans-coded and in this context does have a “deadname” that is used, but that is not the intended interpretation so likely wouldn’t be disturbing
Hellboy is the name chosen by his adopted father, and the name he accepts and uses. The villain uses his demon name, anung un rama, to control him. Hellboy was not aware of this name beforehand
The central character is unhappy with his appearance and modifies his body to make it more acceptable. (On the literal level, this is because he looks like a demon, and the modification is grinding his horns down, but the parallel to more mundane forms of dysphoria is there to be drawn.)
The opening scene involves a LOT of full-screen flashing from a lightning storm in a scene that's already dark. When they open the portal, the flashing is at its worst. It's also VERY bad when Hellboy is first found near the tomb, after the portal closes. My friend who isn't photosensitive also had to look away at times.
At the 52 minute mark, there's a flashback involving intense flashing. The following scene involves a lot of fire, which is not as bad as the flashing but could possibly trigger people.
At 1:47:00 there's intense flashing lights that happen after they enter the water ruins.
Hellboy is born in the 40s making him about 60 in this film, Liz is maybe 20 or 30. Although Hellboy ages differently from humans, he does still appear somewhat older than her and has known her since she was a child