A wolverine is small but one of the most ferocious and brave animals so the creators wanted a small animal like person who wouldn't back down even from the Hulk. read more
In the original concept he was suppose to be a full blown Wolverine/Man mutant, like Sabretooth was but thanks to Chris Claremont he became who we know today. Wolverine was an army name. Logan was his father's name and his actual name is James Howlett. read more
While Wolverine's real name may be James Howlett, to many fans he'll always be known as Logan. I guess that's why his swan song movie is called Logan instead of James Howlett. read more