Wolverine has a superpower that is typically used in a narrow way in the comics to assist him in tracking things. His keen sense of smell almost always points him in the right direction but it could be used for an alternative purpose. Wolverine could sniff through any hero’s secret identity, as long as he’d met them once before.
Wolverine is the stocky, adamantium-boned anti-hero that may be the best at what he does, but what he does involves a lot of evisceration. Logan is a mutant with inherent abilities like a healing factor, animal-like senses, strength, agility, and endurance. The fan-favorite antihero has rarely refrained from using his claws for their intended purpose. But that acute sense of smell has typically been utilized in a limited sense.
Wolverine's super smeller is not utilized to out heroes to a great degree in the comics. But if he wanted to turn in a superhero and unmask their secret identity, he wouldn’t even need to tug at their costume. He could just be in the vicinity of a hero he’s met before and easily peg them if they were in a disguise. He’s tracked down mutants who can shapeshift or blend in with surroundings with his expert nose. So it’s not too far a logical leap that he could identify a disguised hero with ease.
Wolverine's smell is a trait attributed to his mutant powers but is probably drawn from his animal counterpart which can smell prey under 20 feet of snow. Wolverine’s sense of smell is more discerning than that of a dog so he can pick up subtle differences in scents or trace scents that linger for some time. He would make an excellent deterrent at borders or airports where he could sniff out drugs. But he can also pick up small variations in body chemicals and detect if a person is nervous, in danger, or gearing up to attack.
He usually only uses this skill to reveal known enemies. The blue-skinned shapeshifter Mystique is a notable one. She has tried to infiltrate the X-Men mansion multiple times but Logan can pick her out despite whatever disguise she has on due to her unique scent. While he can pick out subtle scents he doesn’t seem all that bothered by pungent odors. He smokes more cigars than Winston Churchill doesn’t seem at all affected by the astringent smell. Perhaps he’s more like a dog than previously thought and is drawn to what would normally be a foul odor to an ordinary human nose.
Wolverine hasn’t had much need or opportunity to unmask a superhero’s secret identity. But if the whim took him, he could expose just about anyone. If Spider-Man made one too many wisecracks about the cranky Canuck, Wolverine could share Peter Parker’s secret with the world. His nose can also pick up perspiration and can aid him in finding out if someone is lying to him. So even if a hero has an excellent poker face Wolverine could probably still trust his nose to tell him the truth.
