Secret Siblings - Cowboy and Nakomis were estranged siblings who were unaware of each other before the airing of the show and revealed it to the rest of the House Guests during week 2.
Twin Twist - Adria Klein and Natalie Carroll were identical twins and would swap places every few days, playing as Adria. If the two made it to week 5 without being discovered or evicted, they would both enter the game as individuals.
Drew Daniel and Diane Henry also revealed that they both had twins, but their twins were not competing in the game.
Pinoy Big Brother: Double Up[]
Double Twin Twist = As part of the season's theme called Double Up, two sets of twins mainly Toffi & Kenny Santos and JM & JP Lagumbay were introduced. Both pair would stay in two separate houses. Every once in a while, the twins have to swap places with their twin in between two houses without their secret being discovered by any of the housemates in two houses. If they failed on their secret task, they would receive a Forced Eviction as a punishment.
Season 17[]
This twist has also appeared on Big Brother 17, following similar rules as it did in Big Brother 5, however it only included the twin twist, not the secret siblings.
Twin Twist - The twist involved twins Liz and Julia Nolan who were both playing as Liz. Despite the houseguests finding out, they both made it to week 5, so they both joined the game as individual players.
Opposite of Big Brother 17, this season did not include the twin twist but instead featured the secret siblings twist. However, the siblings were not estranged and instead knew of the other's presence in the game.
Secret Siblings - A modified version of the "Secret Siblings" twist was implemented in this season. Alex and Morgan Willett entered the house knowing that they would be competing against one another, rather than being estranged.
Big Brother Brazil 17[]
In a variation of the twin twist, Big Brother Brazil 17 had two sets of twins enter on Day 1; a day before the rest of the cast entered. Unbeknownst to the cast; these twins faced an eviction on Day 7, where one twin of each pair would be evicted.
Twin Twist - This modified version of the twin twist was implemented this season. The twist involved brothers Antônio and Manoel, and sisters Emilly and Mayla.
Pinoy Big Brother: Otso[]
Secret Siblings - Just like in Big Brother 5 (US), two estranged siblings who were unaware of each other prior to the show entered the house. Apey Obera and Mark Obera were estranged siblings. They met and reunited through a secret task by Lou Yanong and Abi Kassem. When Mark became a housemate, the two merged into one at first. However, being 2-in-1/Pair Housemate, the relationship of the two did not go well to the point where Big Brother had no choice but to separate the two of them from being 2-in-1 housemates, with the help of the other housemates' and audiences' decision. The two was eventually separated and competed once again as individual housemates.
HaAh HaGadol 1[]
Twin Brothers = Two siblings, Boris and Leon entered the game on day 1. They were aware of each others' existences before they both entered the game.
HaAh HaGadol VIP 1[]
Sisters = Two sisters, Daniella Pick and Sharona Pick entered the game on day 1. They were aware of each others' existences before they both entered the game.
HaAh HaGadol 3[]
Twins = Two identical twin sisters, Rinat and Shiran Gitter, both entered the game on day 1. They were aware of each others' existences before they entered the game.
Big Brother Greece 6[]
On Day 1, Xristos Varouxis entered the house. Later on Day 2, Panagiotis Varouxis entered the house and they both had to make the housemates believe that they were one person.
Big Brother Canada 4[]
On Day 1, Nick & Phil Paquette entered the house. Neither of them knew the other would be competing. Arisa Cox revealed that they would be playing as one person alternating who competes in comps each week but both would remain in the house whether it was their week to play in comps or not.
Pinoy Big Brother: Kumunity Season 10[]
Secret Siblings - Raf Juane and Nathan Juane entered the house as individual housemates. During the first week of the season's Adult Edition, Big Brother gave them a secret task to hide their real identity as siblings to the rest of the housemates as part of the week's weekly task. Succeeding in keeping their secret for the weekly task would give the housemates a luxury shopping budget, and a special immunity for either Nathan or Raf.
Trivia[]
Michael Ellis is the first male to be a participant of this twist.
Michael Ellis and Liz Nolan were the first and second houseguests to participate in this twist and then make it to the Final 2, later followed by Morgan and Emilly.
However, Leon Schneiderovsky made it to the final of his season, ending up placing 5th out of the five finalists.
The Israeli franchise of the show has the most occurrences of the twist, with three.
A similar twist occurred in Big Brother 8 (US) and Big Brother 25 (US), although they used parent-child relationships instead of secret siblings, and in Big Brother 8 the familial relationship was not a secret.
