Tony DiNozzo and Ziva David

Tony DiNozzo and Ziva David are fictional characters from the American police procedural drama NCIS. Tony, an original character, is portrayed by Michael Weatherly, and Ziva, who first appeared in the third season, is portrayed by Cote de Pablo. Frequently referred to by the portmanteau "Tiva" (for Tony and Ziva), the characters' flirtation and the idea of them eventually beginning a relationship became a subject of interest among viewers, and by 2010, TV Guide reported that "many fans have become obsessed with the romantic tension between Weatherly's character and co-worker Ziva". Focus and media coverage on the pair escalated over the years, particularly after NCIS became the most watched television series in America during its tenth season.

The characters were initially scripted as having a "cat and mouse" relationship, something that continues into the later seasons. The pairing develops at a slow pace throughout the series and is dealt a number of obstacles. This includes Tony's "commitment phobias", Ziva's trust issues, a series of other love interests, and Ziva being taken captive and presumed dead between Seasons 6 and 7.

In the season 13 finale, Ziva is killed by a mortar attack arranged by former CIA Agent Trent Kort, and Tony learns that he and Ziva have a daughter, who she named after her sister, Tali. These events drive Tony to leave NCIS to care for their daughter.

Michael Weatherly was cast for the role of Anthony "Tony" DiNozzo in 2003 and has since appeared in every episode of the show. The character is portrayed as "complex": he is a former Baltimore homicide detective with a "heroic spirit" as well as a "total dinosaur in terms of sexual politics".

In the second season finale, NCIS series regular Caitlin Todd was killed off after Sasha Alexander, her portrayer, decided to permanently leave the show. Shortly afterwards, series creator Donald P. Bellisario voiced intentions to replace Todd with another female lead, whom he stated would be "someone foreign who brings a whole new attitude". He expressed hopes that the new character would be drastically different from Todd, who was "kind of uptight".

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