1. Wolverine is only 5' 3". He's as tall as Mila Kunis.
Hugh Jackman is 6' 2". They used tricky camera angles to make him look shorter.
2. Wolverine's senses are so well honed, he can identify shape shifters and sense when people are lying.
It's even been suggested that his sense of smell is so strong, he can smell light waves.
3. Wolverine is probably a liberal.
4. Wolverine's origin story has changed several times. There are rumors that he was originally going to be an actual wolverine that mutated into a human.
And then, at some point, Sabretooth was originally supposed to be Wolverine's father.
5. Wolverine has a son named Daken and a "daughter" who is actually a female clone of himself named X-23.
(Some claim that Daken is a gay character, but writer Marjorie Liu claims that it's more likely that Daken just uses sexuality to manipulate others.)
6. Wolverine is old. Like, 130 years old old.
According to his most recent origin story, Wolverine was born as James Howlett sometime in 1880s. He fought in both World War One and World War Two. He even worked as a covert agent for the CIA during the Cold War.
7. In that time, he's learned 18 different languages.
8. He's also used that time to become an expert in virtually every form of martial arts.
Despite that, he fought Spock once and lost. Yes... Spock. From Star Trek.
He also lost to Squirrel Girl once.
9. Despite constantly being described as a loner, Wolverine has been on more teams that any other character in the Marvel universe.
According to Comic Vine, Wolverine has appeared on 35 different teams.
10. Despite being regularly depicted as a heavy drinker, Wolverine's healing factor makes him much less susceptible to the effects of drugs and alcohol.
11. The lore behind Wolverine's secondary power, his signature claws, is all over the place.
12. The name of the fictional metal grafted to Wolverine's skeleton, "adamantium," is derived from the Greek word "adamastos", meaning "untameable".
13. Wolverine is virtually indestructible. He's bounced back from being run over by a steamroller...
...from been ripped in half by the Hulk and left for dead for over 3 years...
...and even from an atomic bomb blast.
14. He's not totally invulnerable though.
There are also certain materials that suppress Wolverine's healing factor, such as carbonadium and a katana of mystic origin called the Muramasa blade.
15. At some point, Bob Hoskins, Russel Crowe, and Dougray Scott were all considered to play Wolverine in X-Men films.
And before Brian Singer came along to direct the first X-men movie in 2000, Kathryn Bigelow was attached to direct an X-Men film.