Former X Factor stars Jedward said it was an "honour" to return to Celebrity Big Brother, six years after they first took part in the reality TV show.
The Irish singers, who first found fame when they came sixth on The X Factor in 2009, took part in the eighth series of the reality show in 2011.
The identical twins, Edward and John Grimes, 25, were holed up in the house with Kerry Katona and American Pie star Tara Reid, who later got them a cameo in her film Sharknado 3: Oh Hell No!
Ahead of entering the house for the second time, the duo told host Emma Willis: "It's going to be like a great sequel. We're so excited."
They added: "I think we'll get on with everybody, I think everybody needs Jedward the most."
Asked if they will bring a bit of naughtiness into the house, the duo said: "Of course that's us. That's part of us."
The two waltzed into the house in a cloud of smoke and dressed as astronauts before performing for their fellow housemates.
In the CBB house in 2011, the twins learned to shave and embraced the tasks and costumes provided.
Earlier that year they performed their Eurovision entry Lipstick for Barack Obama and his wife Michelle on their visit to Dublin in 2011 and said the president was a fan of their trademark quiffed hair.
The duo released new single Oxygen earlier on Friday and recently said 2017 will be a "Jepic" year.
They entered the house just moments after it was revealed actor James Cosmo would be automatically facing the first live eviction.
The Games Of Thrones star was not selected by All Star celebrities Jamie O'Hara and Angie Best who had the chance to save the "edited out" housemates.
It was also revealed that the edited out celebrities, including singers Stacy Francis and Ray J Norwood, DJ Brandon Block and model Bianca Gascoigne, will not be allowed to nominate for the first eviction.