The "Anchorman" star has accepted a challenge from Smith to a "drum battle" to benefit the charity Cancer for College, which grants college scholarships to cancer survivors.
It all started when Ferrell did an AMA ("Ask Me Anything") on Reddit last week and wrote, "It has been acknowledged many times that myself and Chad Smith, drummer for the Red Hot Chili Peppers, share a resemblance to each other. A lot of people think that it's me playing for the Red Hot Chili Peppers. But that would be an insult to Chad Smith. The truth of the matter is there is no Will Ferrell. Only Chad Smith."
Then the "rivalry" officially became a thing when the two addressed one another in a set of videos on Funny or Die's Instagram page.
"I just want everyone to know that I had a great time on Reddit, and it was great to finally clear up the fact that I am actually Chad Smith," Ferrell deadpanned in his video.
Smith responded by telling Ferrell to "stop impersonating me" and challenging him to a drum battle. "I've seen your skills -- you don't got 'em," he added.
As Ron Burgundy would say, things escalated quickly. When Smith did his own Reddit AMA on Feb. 7, Ferrell made the face-off official.
"Hi, Chad. Will Ferrell here. I saw your video and I graciously accept your invitation to a drum battle," he wrote. "If we can raise $300,000 for Cancer For College I will face off with you in the greatest drum vs. cowbell showdown the world has ever seen. We can do it on stage at a Red Hot Chili Peppers concert or in front of a mutually convenient public library. Your call."
Smith happily accepted, writing, "Bring IT!"
Cancer for College then tweeted a link to a fundraising website where fans help make the battle happen by donating to the cause. Those who do will be entered for a chance to hang out with Ferrell at his Desert Showdown charity golf tournament in Palm Springs, Calif., next month.
There's no word yet on when or where the charity battle will happen, but there's at least one other musician that also wants to work with Farrell. During his AMA, Snoop Dogg chimed in and posted, "ayy Will, imma need some more cowbell on tha next album, u game?"
The actor replied, "I'm absolutely game, Snoop. I've also got some beats that I want to run by you. I'm warning you now, they're not good."