After years of working closely with humans, Hellboy chose to be one too, meeting brilliant and sometimes tragic people on his adventures with the Bureau for Paranormal Research and Defense. But, given that he is the son of Azzael, an Archduke of Hell, Hellboy also has a demonic form under the name Anung Un Rama, adding a terrifying side to him. However, this does not mean he is helpless in his humanoid form, as his Right Hand of Doom does most of the talking during a fisticuff. But sometimes, bigger enemies require a bigger hand, and it is for this purpose that Hellboy recently got himself an enormous metallic look.
Source：https://www.cbr.com/hellboy-giant-robot-explained/
