Carey dressed up in drag as the rapper while filming her new music video "Obsessed" in New York City Monday.
The tune's lyrics include: "You're so lame ... Ooh boy, why you so obsessed with me? Ohh finally found a girl that you couldn't impress/Last man on the earth/still couldn't get this."
Eminem rapped about Carey -- who he has said he briefly dated in 2001 -- in his song "Bagpipes From Baghdad."
"I want another crack at ya," Eminem's lyrics go. "Nick Cannon better back ... up. I'm not playing, I want her back, you punk."
Slammed Carey's husband Nick Cannon then: "What type of grown ... man lies about getting with a chick? Only Slim Lamey! LOL!"
Eminem later admitted to BBC Radio he "kind of spazzed out on that record."
"There's a line on there that was a little harsh. It's a harsh line ... But it's like this, the way I look at it. I had no idea he was going to take it like he took it. I had no idea Nick Cannon was going to start wildin' out on me," he said.