The holiday flick isn't the last movie that will be released featuring Williams -- he's also in Night at the Museum: Secret of the Tomb (Dec. 19) and the animated movie Absolutely Anything -- but it is the last movie that he filmed before his untimely death.
Williams had been battling with severe depression in the days leading up to his August 11 suicide. When the news broke, McHale remembered his co-star in a tweet, writing, "RIP @robinwilliams You were one of the very best that ever was. You were one of my heroes."
A Merry Friggin' Christmas also stars Lauren Graham, Candice Bergen and Clark Duke.