Former "Superman" actor Dean Cain ridiculed "Last Week Tonight" host John Oliver on Monday over his monologue claiming Immigration and Customs Enforcement (ICE) was "f---ed" if they let the actor join its ranks.Near the end of his show on Sunday, Oliver mocked both ICE and Cain over news that ICE had removed its age limits and would be swearing in the "Lois & Clark: The New Adventures of Superman" star as an "honorary ICE officer.""You know, there's an old saying in Hollywood: If all you can get is Dean Cain, you are f---ed," Oliver said on his show."Now, I'm not saying that ICE isn't finding people. I'm just saying, when you are reduced to pinning a badge on the 59-year-old star of 'The Dog Who Saved Christmas,' 'The Dog Who Saved Christmas Vacation,' 'The Dog Who Saved the Holidays,' 'The Dog Who Saved Halloween,' 'The Dog Who Saved Easter,' and 'The Dog Who Saved Summer,' maybe you are in trouble."JOHN LEGUIZAMO TORCHES DEAN CAIN AS A 'LOSER' FOR JOINING ICE, BUT SUPERMAN ACTOR OFFERS GENTLE REPLYHe added, "Although, on the plus side, no need for that guy to wear a mask because the chances of anyone recognizing him are f---ing zero."Cain mocked the HBO host in kind on X the next morning."He stole that mask joke from the internet -- and he also laughed hysterically when Trump said he was going to run for President. Case closed. (and those movies were sweet, by the way!)," Cain wrote.During the show, Oliver also gave advice to viewers on how to interact with ICE agents, telling them to only say "Am I free to leave?" and "I want to speak to a lawyer.""And I recognize that in some cases you may be unable to help yourself from saying, 'Didnt you used to be Superman? I thought you died. I cant believe Im meeting a filmmaker, but that really is it," Oliver joked.FORMER SUPERMAN ACTOR DEAN CAIN SWORN IN AS RESERVE POLICE OFFICERCain will be sworn in as an honorary officer in the coming month, assistant secretary Tricia McLaughlin, the Department of Homeland Securitys spokesperson, said. Although it wasnt immediately clear what his duties as an honorary officer would entail.In an interview with Fox News Digital, Cain described joining ICE as a way to show support for the officers that he believes were being "vilified" for doing their jobs."If you're a legal citizen here in this country, no worries, you're great, but if you're here illegally, you've broken the law to begin with, whatever the circumstances are. You had multiple opportunities to self-deport, and the fact that these men and women who are doing their jobs are getting vilified, I had to stand up with them and for them, because I think it takes people standing up to change the culture," Cain said.Cain also defended joining ICE during a heated debate with anti-Trump The Bulwark host Tim Miller on "Piers Morgan Uncensored" on Monday."Now we've got ICE agents and, apparently, former Superman actors who are going to jump out of vans and nab them and hold them in deportation cells. That's insane. Like, that's not how you act in a free country," Miller mocked.CLICK HERE TO GET THE FOX NEWS APP"I'm not untrained," Cain shot back, bringing up how he became a deputy sheriff and a reserve police officer nearly a decade ago."So, I don't know why you're saying untrained. And by the way, when you join ICE, they train you. So, to say that and try to denigrate because I'm an actor, I shouldn't be able to be concerned about what's going on with our borders or with our law enforcement agencies is denigrating. It's ridiculous. Should I say because you're a former Republican strategist, you have no say on anything? That's baloney," he added.