Cena responded to Dwayne The Rock Johnson who jokingly threatened him the night before on the same show.
The People’s Champion told Kimmel: “If he ever acts up I will knock his teeth so far down his throat that he’ll stick a toothbrush up his a## to brush them.”
The Champ then acted like he was offended and hurt by the 10-time world champion’s comments.
Cena, who was promoting his newest movie Blockers, said: “I’m not gonna take that.
“Listen up, Dwayne Johnson – if that is your real name.
“Cause everyone around the world knows that your first name is T and your last name is Herock. You just pronounce it all stupid and that gets me even more p##### off.
“Listen, listen if you think you’re making threats to me but thinking shoving a toothbrush up my bum is a threat I got some advice for you pal – and by pal I totally mean my best friend and I don’t mean it in adversarial terms.
“Watch Blockers and then watch it again because if you think shoving a toothbrush up my butt is a threat you got news coming pal.
“There’s been a funnel up there, there’s been a parking cone, there’s more traffic in that region than a Monday on a 405 in both directions.”
Cena is expected to appear at WrestleMania 34 even though he is not booked to wrestle anyone.
The Champ has been calling the Undertaker out for four weeks but The Deadman has snubbed his WrestleMania challenge.
However, rumours suggest Taker will return at Mania to face the 16-time world champion.
