Who’s joining Jimmy Pardo, Matt Belknap and Pat Francis for their eighth annual Pardcast-a-Thon, happening for 12 hours this Saturday live from Flappers Comedy Club in Burbank, Calif.?

Among the known, announced guests: Jon Hamm, Sarah Silverman, Lauren Ash, Paul F. Tompkins, Scott Aukerman, Randall Park, Kumail Nanjiani, Rachel Bloom, and Rhett and Link.

Of course, who knows who else might drop by to lend a hand and their voice to the festivities, which have raised more than $650,000 for Smile Train through donations and auctions.

You can’t get a ticket to see it all in person, unless you snagged one before it sold out, although you can watch all 12 hours live onscreen via the Never Not Funny site. Runs from Noon to Midnight Pacific time (3 p.m. to 3 a.m. Eastern).

You also can make donations directly to Smile Train

OR…

You can place your bids on the auction items on eBay, which include autographed posters, a recorded message for your phone by Sarah Silverman, a 45-minute Skype session with Paul Gilmartin, guest slots on Getting High with Doug or Doug Loves Movies, lunch with Pardo, and more!