Why does the wolverine say bub?

What is this? In the ‘X-Men’ film series Wolverine used to call people ‘bub’. The term bub means fellow or buddy in the films.

What is Wolverine’s catchphrase?

Artist Frank Miller collaborated with Claremont and helped revise the character with a four-part eponymous limited series from September to December 1982, which debuted Wolverine’s catchphrase, “I’m the best there is at what I do, but what I do best isn’t very nice.”