Trevor Bruttenholm, the English academic who raised Hellboy is an admirable character for taking care of Hellboy as a child despite his inhumanity. He fights against the attempts by the Nazis to use the occult improve their fortune in the second World War as they begin to lose.
Later, he becomes director the Bureau of Paranormal Research and Defense (B.P.R.D.) where he is in charge of addressing paranormal threats to humanity. Later he gets captured by Rasputin who attempts to unleash the Ogdru Jahad which could lead to the world’s destruction. Although Bruttenholm is killed in the process, he does his best to use his scientific expertise to save the human race and serve the common good. This makes him a likeable character. He is also the adoptive father of Hellboy and is responsible for humanizing him and setting him on the path towards harmony with the human race when he could have gone in a very different direction.