Watch: X Factor stars Chico, Stevi Ritchie and Wagner enjoy a reunion on This Morning
The singers were big hits in the early days of the competition, with Chico competing in 2005 and Wagner taking his stab at pop success in 2010.
But both looked very different when they joined fellow former contestant Stevi Ritchie on the ITV show.
Chico was known for his cropped dark hair, but had grown it long and was wearing it in two long plaits.
It left fans joking that he was channelling the character Wednesday Addams, who is currently being played by Jenna Ortega in hit Netflix series Wednesday.
“Chico channelling Little Bo Peep,” quipped another viewer on Twitter.
“Chico has the Laura Ingalls look from Little House On The Prairie,” teased another fan.
Wagner – who has been open about undergoing a hair transplant - always sported long hair.
But the star, who appeared on the show via video, has now teamed his lengthy blond locks with a full dark beard and moustache.
“Is that Wagner?” asked one viewer.
“What the hell has Wagner done to his beard?” said somebody else.
Despite the makeovers, viewers agreed they loved the trip down memory lane.
“Wow Chico, Wagner and Stevi... good old days of X Factor,” posted one person.
Another fan said the pair were “legends”.
The X Factor was created by music mogul Simon Cowell and started in 2004.
It last aired in 2018, with a celebrity version in 2019.
ITV has said there are "no plans" for another series - although last year there were rumours that another channel could pick up the format.