Katie and Sadie were introduced to the island as Best Female Friends For Life, (or BFFFL's as they call it) and they were extremely stereotypical. They met at their childhood and were inseparable friends since then. In Total Drama Island, their friendship is many times used as a gag, with things such as them doing absolutely everything together, and sometimes even syncing each other (such as in The Big Sleep, where they snore together). They sometimes reached delicate points in their friendship (such as when they were fighting over Justin), but in most of the season they are almost naturally seen as great friends. They interact in virtually all the episodes where they are seen together, and many times share good memories from their childhoods (often through rambling), which indicates that their friendship was, in most of their lives, at the same status as it is today. Katie is tan and petite, while Sadie is white and generally overweight, being the near-only major difference between the two.
Katie, labeled The Sweet Girl, was a camper on Total Drama Island and a member of the Killer Bass. She did not compete in either Total Drama Action or Total Drama World Tour, but appeared in the Total Drama Aftermath as a commentator.
Sadie, labeled The Sweet Girl's Friend, was a camper on Total Drama Island as a member of the Killer Bass. She did not compete in either Total Drama Action or Total Drama World Tour, but appears in the aftermaths as a commentator.