5) Hellboy
Probably the most unconventional – and the only non-Marvel/DC character to boot – detective on this list is Hellboy, created by Mike Mignola for Dark Horse Comics and known to the world at large thanks to Ron Perlman’s big-screen portrayal (soon to be rebooted by Stranger Things’ David Harbour).
Originally summoned to bring about the Apocalypse, Hellboy was adopted by the kindly Professor “Broom” Bruttenholm and grew up to fight alongside the Bureau of Paranormal Research and Defense against occult threats. As such, the character isn’t strictly speaking a detective but he is often called the World’s Greatest Paranormal Investigator, due to his considerable expertise in solving supernatural cases.
Jaded and unflinching in the face of pure evil and giant monsters and with a wry putdown on hand for every occasion, Hellboy has the personality of a classic pulp detective… he just happens to look like a demon from the pits of hell.