The blink-and-you'll-miss-it appearance came after the late-night host won a role as an extra in a charity auction
"Harold and Kumar" star will reunite with former co-star Neil Patrick Harris for significant recurring role
Former "SNL" comedian will replace Dave Foley, who was introduced during season finale
CBS also picks up pilots from Tad Quill, "Chuck's" Josh Schwartz
CBS launches a viral video featuring the beloved holiday icon like you've never heard him before. Blame it all on Neil Patrick Harris.