Rivals mock Donald Trump in first minutes of GOP debate

(L-R) Ben Carson, Ted Cruz, Marco Rubio and Jeb Bush pose together at the start of the debate in Des Moines,  January 28, 2015.

Carlos Barria/Reuters

Donald Trump was absent from Thursday night's GOP debate in Iowa, but the GOP front-runner still dominated the conversation during the forum's first five minutes.

Asked about the "elephant not in the room" by Fox News moderators, two rivals -- Texas Sen. Ted Cruz and former Florida Gov. Jeb Bush -- mocked the billionaire businessman.

"Let me say I'm a maniac, and everyone on this stage is stupid, fat and ugly," Cruz deadpanned. "Now that we've gotten the Donald Trump part out of the way, I want to thank everyone here for showing the men and women of Iowa the respect to show up."

Cruz later made a pitch to Trump's supporters, saying that he is still "glad Donald is running" and "glad he has produced enormous enthusiasm."

"Every Donald Trump voter or potential voter, I hope to earn your support," Cruz said.

"If Donald engages in insults or anybody else, I don't intend to reciprocate. I have not insulted Donald personally and I don't intend to," he continued. "Now there is a difference between personal insults and attacks, between going into the mud with ad hominems and focusing on issues and substance...That's fair game, but that's where I'm going to focus, that is how I focused from the beginning of the campaign and it's how I intend to continue going forward."

Jeb Bush, who has been the target of several Trump attacks over the course of the campaign, later deadpanned his response to the front-runner's debate absence.

"I kind of miss Donald Trump. He was a little teddy bear to me," Bush said, to loud laughter from the debate audience. "We always had such a loving relationship during the debates, and in between the tweets. I kind of miss him. I wish he was here."

Bush also slapped at his fellow Republican candidates, who he said were "in the witness protection program" while he alone "went after [Trump] on behalf of what the Republican cause should be -- conservative principles, believing in limited government, believing in accountability."