Hellboy's powers and abilities
Hellboy's superhuman abilities would seem to stem from his demonic nature. While his specific powers and abilities have never been explicitly listed, Hellboy is much stronger and more physically durable than an ordinary human.
Accelerated Healing / Regeneration
Although he can be burned and damaged like any living thing, Hellboy possesses a "healing factor" that allows him to recover from wounds at an incredible rate. One example of this was when he once took a sword thrust through his chest. In the movies, he is depicted as being fireproof, but in the comics, he can still burn; however, his accelerated healing may still give off the illusion of being immune to fire. He has been savagely beaten by large monsters on several occasions and survived, often with relatively minor injuries. On one occasion, Hellboy directly charged an MG-42 machine gun and took numerous bullets to the chest before destroying it.
Hellboy seems to age differently from normal humans. At the time that young Hellboy tried his favorite food, "pamcakes" for the first time, he was technically two years old but appeared to be far older, around age six. In 1954 he already appeared to be a full-grown adult but was in reality about ten years old. His rapid physical maturation is in contrast to his physical rate of aging, which seems to be much slower than normal. Throughout the sixty-year span of his life, Hellboy seems to have ceased to age ever since reaching physical maturity.
Hellboy assumes an even more demonic form under special circumstances, either artificially or when under emotional duress. In this form, Hellboy's stumps become full-grown horns. After coming to terms with his heritage, Hellboy seems to be able to transform at will, while also sprouting wings. Hellboy becomes much stronger and gains access to his latent magic. In his full-demon form, Hellboy was able to effortlessly slaughter Hell's most powerful inhabitants.
In his demonic form, Hellboy has been shown to increase his size at will. With his size-shifting, Hellboy can increase his size to the point where he's as large as Leviathan and Behemoth, two giant demon beasts he faced in the past. Upon increasing his size, Hellboy becomes a much more threatening destructive force and almost unstoppable when combined with his already impressive power set in his demon form.
While in his demonic form, Hellboy has the power to control the fires of Hell. With the power of Hellfire, Hellboy can create and manipulate massive devastating infernos from his body that obliterate anything in their path.
In his demonic form, Hellboy has the power to command lightning from the sky and strike down whoever he wishes.
When transformed into his demonic form, Hellboy sprouts wings which grant him the power of flight. However, it's unknown whether he uses wings or magic to achieve this feat.
Hellboy has been noted to have advanced sight, allowing him to see farther than average humans. The extent of his sight ability seems to be limited to distance, but he's shown to not have too much trouble seeing in the dark or in minimal-light situations.
Despite being taken out many times and eventually stopped at one point, Hellboy seems to have escaped death at nearly every turn, possibly because he could fulfill his duty as the bringer of the apocalypse. As he's described to be "as deathless as Koshchei", Hellboy can't die unless he believes he should.
Hellboy is shown to be capable of withstanding wounds that would be fatal to ordinary humans without being incapacitated, as well as recovering from injury at an incredible rate. He has been shown to withstand great impact forces, high caliber bullets, exposure to extremes of both temperatures and falls from great heights. He has been savagely beaten by large monsters on several occasions and survived, often with relatively minor injuries. On one occasion, Hellboy directly charged an MG-42 machine gun and took numerous bullets to the chest before destroying the gun. On another, he was impaled by a massive spearhead through the chest, but smashed the handle and charged the attacker, leaving the spearhead buried in the tree behind him.
Although certainly not limitless, Hellboy's stamina has been shown to exceed that of normal and highly athletic humans. Hellboy's stamina is part of what keeps him going in a long battle and the factor that backs up his stubbornness as he refuses to go down in a fight.
The extent of Hellboy's strength is unclear, but he has, for example, torn down a large tree and hurled it at an opponent. He has also thrown opponents weighing at least four to five hundred pounds.
Thanks to his demonic heritage, Hellboy's body is quite resistant against high temperatures and fire without feeling discomfort on several occasions. In the movie version, he even more resilient against heat or burns than his comic book counterpart does, to the point became immune to all forms of fire and burns, including Liz Sherman's flames, and electrocution.
Although proficient with handguns, Hellboy often chooses to engage in close combat where he can utilize his incredible strength to defeat his enemies. He has also displayed skill with swords and other improvised weapons.
Due to his demon heritage, Hellboy was born with the ability to read, comprehend, and understand a number of ancient, magic and demonic languages. Additionally, Hellboy has also worked with the B.P.R.D. for a number of years, thus if there was a language he didn't know innately, there's no doubt he'd have come across it in his work.
His decades of experience as a paranormal investigator has given him expertise in folklore, magical rituals, the use of charms and curses, paranormal creatures and other related topics.