WATCH: How Tucker Carlson and Rachel Maddow formed their chummy on-air relationship while working at MSNBC

• Fox's Tucker Carlson and MSNBC's Rachel Maddow used to be chummy when they worked together on MSNBC.

• Maddow was a panelist on Carlson's MSNBC show in 2005 called "The Situation with Tucker Carlson."

• Rachel Maddow recently spoke highly of Carlson, telling Vanity Fair that he's "doing great right now."

Cable news opposites Rachel Maddow and Tucker Carlson have a shared history.

Maddow recently credited Carlson with giving her a foot in the door at MSNBC when she was a panelist on his show "The Situation with Tucker Carlson" from 2005 to 2008. At the time, she was a talk show host on Air America Radio.

"The first show I worked on was his 11 o'clock show on MSNBC that nobody remembers. But he was always kicking around the business and has always been talented. It just — this turned out to be his moment," she said in an interview with Vanity Fair.

According to the New Republic, Carlson's team brought Maddow onto his show in 2005, and he insisted on keeping her around even though "she didn't look like a Fox blonde," a style reportedly preferred by MSNBC's then-president.

When Carlson was later hired at "Fox and Friends" in 2013, Maddow told Salon, "Tucker and I agree on just about nothing, but he has always been kind to me, and a fun person to fight with. I wish him all the best."

Carlson would then go on to host "Tucker Carlson Tonight" on Fox News, and Maddow "The Rachel Maddow Show" on MSNBC.

Here's a look-back into their time together on-air where they regularly quipped and exchanged laughs amid their fiercest debates.

Carlson said he would 'pay cash' for a video of Maddow and conservative pundit Ann Coulter.

In a June 2006 segment on Carlson's show, he and Maddow discussed conservative commentator Ann Coulter and her 2006 book "Godless: The Church of Liberalism."

"It turns out not everyone agrees with Ann Coulter," Carlson said. "Joining us now, someone who most likely falls into that category, Air America radio host Rachel Maddow."

"She's actually an ex-girlfriend of mine. Little known fact," Maddow joked. "So it's a lot—it's very personal. A lot of our disagreements are personal. But I can see her politics, too."

"You got the video, I'll pay cash," Carlson said. "No, excuse me."

They debated gay marriage and joked about banning divorce.

In another June 2006 segment, they discussed a proposed constitutional amendment banning same-sex marriage.

"The euphemism here is the whole idea that gay marriage is somehow more dangerous to marriage than divorce is, right?" Maddow said near the end of the segment.