(Exclusive) Will Ferrell's Son Magnus, 20, Attends You're Cordially Invited Premiere, Reveals How Dad Got His Song Into Movie ... and Harper Steele on Their 30-Year Friendship and Emotional ...

Arguably one of the biggest stars to come out of SNL, Ferrell has made a name for himself in the comedy world with his quippy one-liners that fans throw at each other and even at him in public.

Matt Baron/BEI/Shutterstock; Michael Buckner/Variety via Getty Will Ferrell's parents are major fans of his new documentary ... "Having known somebody for 30 years, it's different than if you ...