Rachel Green and Ross Geller from the show Friends are sometimes compared to Harley Quinn and the Joker from the DC Comics. Both couples are considered toxic, but the Joker and Harley Quinn relationship is considered more toxic. Harley Quinn was introduced in the comics in 1999 as the Joker’s sidekick, lover, and best friend. As a doctor, Harley is aware of the Joker’s evil, but she still tries to get his attention. Harley has given birth to the Joker’s child and twins in different DC Comics universes. Rachel and Ross have an on-again off-again relationship throughout the series. Ross has an outburst when Rachel doesn’t say goodbye properly, and Rachel has dated Ross’s friend Joey.