Doctor Osmium: Two Fisted & Six Fingered Scientist-Adventurer (with thanks to @Ms_Entropic)
His lost parents uncovered the secrets of human germ plasm before they were killed. Some of their secrets he has inherited, others remain a mystery. Engineered for perfection Doctor Oswald Stone is a perfect biological mechanism. Born with a grand physique, a near-unequalled mind, an unknown degree of longevity, perfect and extended eyesight and - most unusually - an extra thumb on each hand he explores the world trying to understand the normal human condition and the rolls of genetic chance that gave rise to the only genius that outstrips his own - that of his father. In the process he battles inhuman threats, chases cryptids and battles the unnatural and twisted intellects and physiques that nature throws in his way. One to each hand are tattooed the letter 'Reason' and 'Method'.
Mimsy Burogrove: Psychedelic Detective
The 60s is bit out of the pulp era, but what the hell. Mimsy Burogrove is a half-Indian, half-British psychic who solves crimes and mysteries of the mind despite being a tiny, tiny woman almost entirely swallowed up in her voluminous kaftan. The best things come in small packages and
Tessa Coyle: Science Police
Originally conceived of for a comic strip - that I still want to write - this comes from the background of the '45 game where Science City Zero is a hidden redoubt of science and civilisation in an atomic wasteland. The science police deal with runaway experiments or those who transgress The Rules. Partnered with a robot she deals with these problems in a city that's one third The Jetsons, one third Gernsback Continuum and one third Frankenstein.
The Black Rat
A 'masked avenger' whose knowledge of London's literal underworld aids him in his endless battle against the metaphorical one. Clad in black he is almost invisible in the night and the fog, his origins a mystery, the reason for his war lost to time. He haunts the sewers and The Underground, turning up - unbidden - to wreak vengeance on the criminal and the cruel.