Ramis is best known for his onscreen work as Egon Spengler in 1984's blockbuster film "Ghostbusters" and Bill Murrey's sidekick Russell Ziskey in the 1981 film Stripes.

Off the screen, Ramis directed and co-wrote a string of iconic movies. His writing and co-writing credits include National Lampoon's Animal House, Meatballs, Caddyshack, Ghostbusters, Back to School, Groundhog Day, Analyze This, Year One and many more.

Ramis also directed a string of hit movies including Caddyshack, Groundhog Day, National Lampoon's Vacation, Analyze This, Year One, Analyze That, Multiplicity and more.

United Talent Agency spokesperson Chris Day said that Ramis died from complications of autoimmune inflammatory vasculitis, a disease that involves swelling of blood vessels, according to the New York Times.

Several entertainers posted tributes to Ramis online on Monday. Seth MacFarlane had this to say, "Harold Ramis was a brilliant, shining example for every comedy writer hoping to achieve excellence the field. He will be sorely missed."

Justin Timberlake tweeted, "Caddyshack. Griswalds. Egon Spengler was always my favorite Ghostbuster. Genius. My condolences to Mr. Ramis's family. #RIPHaroldRamis."

Billy Crystal wrote, "Sad to hear my friend Harold Ramis passed away. A brilliant, funny, actor and director. A wonderful husband and dad. Big loss to us all."