Jimmy Kimmel might be earning headlines for his ongoing feud with President Donald Trump but his on-screen rivalry with Matt Damon is still very much active as well.

In particular, the 57-year-old Kimmel was in for an unwelcome surprise on a recent episode of his ABC talk show, Jimmy Kimmel Live!

On October 3’s episode, Kimmel spoke about New York’s educational mascot, Frankie Focus, a large green monster character meant to promote attention among ordinary students.

Inviting “Frankie” out on stage at the tail end of his monologue, Kimmel asked the furry green creature to explain the importance of attention in school, only to receive some biting jokes in return.

“Why is it so important for kids to pay attention in school, Frankie?” Kimmel asked.

“Because if they don’t, they’ll never get a college degree,” Frankie explained. “Jimmy, did you get a college degree?”

When Kimmel bashfully responded that he hadn’t, Frankie cheerfully observed, “I could tell from watching your stupid monologue.”

Following a few more barbed comments from each, Kimmel removed the “hot green sewer Labubu”s mask, revealing Frankie Focus to be none other than Good Will Hunting star, Matt Damon.

As the thunderous applause died down, the 54-year-old Damon explained that he simply tried to get on Kimmel’s “last show ever” as comically emotional music played in the background.

“I wore this costume because this is the last chance to get on the show,” Damon said. “I know we’ve had our differences over the years, but I wanted to be here tonight for your last show ever.”

When Kimmel pointed out that Jimmy Kimmel Live! wasn’t ending, the Bourne star acted with confusion.

“But the president canceled you, which I was a big fan of by the way,” Damon said. “When he said you had like zero ratings and no talent, I was like, ‘I’ve been saying that for years!’”

After Kimmel said he wasn’t canceled, but merely off the air for three nights, Damon went on to say, “Is there like some kind of repeals process?”