Before Triumph interviewed Cruz, he spoke to his opponent, O'Rourke.
'Does it concern you that half your base thinks they can vote through Instagram?', Triumph asks, drawing a laugh out of the Democrat.
He also references the "Cruz is the Zodiac Killer" joke by saying that Cruz's stance on repealing Obamacare would kill way more people than the Zodiac ever did.
When asked why she chose to support O'Rourke at the polls, Aguirre told the reporter, "Because he represents everything that Donald Trump isn't".
After interviewing the candidates, Triumph (pictured on The Late Show) joined in with Cruz supporters to chant that he is a "lion of the Senate". Without giving them all away, here are the seven sickest burns Triumph lands on Ted Cruz.
The singer joins a number of other celebrities - including fellow Houston native Travis Scott - who have voiced support for the candidate. "Because he's a disgusting fish monster!"
'I love the way you are anybody but Ted Cruz, ' Triumph, as played by Colbert's former colleague Robert Smigel, told O'Rourke during their interview. "Is that covered under the GOP healthcare plan?"
"Just remember: It wasn't the Republicans, it was the Democrats that took you into the vet to get fixed and there is freedom on the other side", Cruz cracked as his supporters laughed. "I'm not 'overwhelming scientific evidence of global warming'".
"Because he represents everything that Donald Trump isn't", the voter insisted.
Given that Conan O'Brien's TBS show "Conan" is on hiatus, Colbert explains at the start of the segment above, O'Brien was happy to loan one of his correspondents, Triumph the Insult Comic Dog, to Colbert.