Donald Trump. REUTERS/Mike Stone Republican presidential frontrunner Donald Trump continued his attacks against rival Marco Rubio at a rally in Arkansas on Saturday, mocking his ears and much, much more.

Trump's attacks on the Florida senator came after Rubio went on the offensive against Trump at a Republican debate on Thursday.

"This guy has a fresh mouth," Trump said of Rubio on Saturday. "He's a very nasty guy."

Trump also touted his endorsement from New Jersey Gov. Chris Christie and referred to a previous debate in which Christie, a former candidate, went after Rubio for repeating canned lines:

I saw a meltdown of a human being like I've never seen. It was Rubio. ... [Christie] started and he looked at Rubio and they went back and forth and all of a sudden. ... I watched Chris go after this lightweight ... and he's over here, and I see him starting to sweat like I have never seen anything like it.

"Thank God he has really large ears, the biggest ears I've ever seen," Trump added, "because they were protecting him."

He also said of Rubio: "I have never seen any human being sweat like this guy."

Trump continued to rail against Rubio at length in his speech. Trump, who vowed Friday to "open up" libel laws to make it easier for public figures to sue the media for besmirching their records, expanded the idea to politicians like Rubio.

"I listen to this light, little nothing say, 'Trump's a con man,'" he said of Rubio. "Isn't it a disgrace? I mean, seriously. It really is — maybe we'll make the libel laws also so we can sue lying politicians. "

Marco Rubio. J Pat Carter/Getty Images

Trump also predicted he would easily defeat Rubio in his home state of Florida because everyone supposedly hates him there.

"Rubio's won nothing. He couldn't get elected dogcatcher in the state of Florida. They hate him in the state of Florida. ... They hate him in Florida," he said.

As he has done previously, Trump also taunted Rubio for putting on "makeup" at their debate earlier in the week, and for sweating to an extreme amount at a debate earlier in the month.

"I have never seen a human being sweat like he sweats," Trump said.

Trump's insults follow Rubio mocking him at a Friday rally, where he took out his phone and proceeded to read Trump's Friday-morning tweets in which he attacked Rubio.

"I have them right here. Let's read some!" Rubio said with glee. "We'll have fun."

Rubio read the first Trump tweet, which accused Rubio of being a "choker" but misspelled the term.

"And once a chocker, always a choker," Rubio said, feigning confusion. "I guess that's what he meant to say. He spelled 'choker,' 'c-h-o-c-k-e-r.' Chocker."

Rubio then referred to Trump's dubbing of Rubio as "Mr. Meltdown." He said that during the commercial breaks it was actually Trump who was melting down amid Rubio's attacks.

"First, he had this little makeup thing, applying makeup around his mustache, because he had one of those sweat mustaches," Rubio said.

Rubio also went after Trump at campaign stops on Saturday, wondering why "a guy with the worst spray tan in America" was attacking him for putting on makeup at debates.

The senator continued mocking Trump's appearance.

"Trump likes to sue people," Rubio said. "He should sue whoever did that to his face."

Colin Campbell and Brett LoGiurato contributed to this report.