Nagini. Yes, that is right – Maledictus Nagini does not appear in the third
Fantastic Beasts movie.
This may be simply because actress Claudia Kim was not available at the time of the delayed filming, which took place between September 2020 and February 2021, having given birth to her daughter at the end of September or beginning of October 2020.
Alternatively, it's possible that Nagini was intentionally written out of the third movie during script rewrites; one of the criticisms of Fantastic Beasts: The Crimes of Grindelwald was that there were too many characters to follow. Or perhaps she was never intended to be in the third film to begin with.
Nagini was a surprise character introduced to the Fantastic Beasts series in the second movie, when it was revealed that Lord Voldemort's eventual pet snake was actually a Maledictus, a human inflicted with a blood curse that would transform them permanently into a beast. In Crimes of Grindelwald, Nagini meets Credence at the Circus Arcanus and is his companion during his quest to find his identity.
What do you think this means for the series going forward? Will we eventually get to see how Nagini becomes associated with Voldemort?