Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
You probably need to have a Hogwarts master's degree in the Harry Potter wizarding world to understand everything that's happening in this sequel to "Fantastic Beasts and Where to Find Them" the 2016 prequel to the Harry Potter movies, but if you have seen the first one, you'll get the gist. Obviously they need to withhold information to make you want to watch the next 88 movies in the series, but that was fine with me after they introduced the beautiful snake-woman Nagini (Claudia Kim). I'll be checking in to find out if she shows up in the next one, and I hope she has a bigger part.
Before Nagini shows up, we see some other CGI monster snakes used as weapons. Grindelwald, played by albino Johnny Depp, is escaping from a carriage pulled by flying horses inside of which a guy disguised as Grindlewold is being held at wand point. Grindelworld shoots his wand and turns the reigns into two giant snakes that leap fangs first into the face of some unlucky guy who goes flying. Then Grindelwartd gets rid of all the other guards and escapes. For some reason, the man disguised as him ends up with a forked tongue. It's a good look on him, but I hope it doesn't start a trend.
Nagini gets to show off later when we're in the Wizarding World, an alternate universe to the Non-Magic world which is populated by the Muggles, the No-Maj, the Can't Spells - names the wand-wigglers use to describe non-wizards. (The basic plot is that Grindelwhiz and his wizard followers want to take over and rule both worlds and the good guy wizards want to stop him.) In Magic Paris, an overly-bearded impresario named Skender has set up a carnival freak show called Cirque Arcanus where he keeps Nagini behind bars. She's his main attraction because she can change into a snake in front of the audience and who wouldn't pay to see that? (The carnival poster advertising her uses an animated snake, one of the perks of buying ad space in the Wizarding World.) Nagini has made plans to escape from Skender with the help of a guy named Creedence Barebone.
At show time Skender introduces Nagini's act, saying:
"Next in our little show of freaks and oddities, I present to you a Maledictus.
Once trapped in the jungles of Indonesia, she is the carrier of a blood curse.
Such Underbeings are destined through the course of their lives to turn permanently into beasts.
But look at her. So beautiful. Yes. So desirable.
But soon she will be trapped for life in a very different body.
Every night when she sleeps, mesdames et messieurs, she is forced to become... she is forced to become... she is forced to become..."
[She hesitates, but finally rolls around and transforms into a snake. Oddly, her clothing disappears also, then somehow re-appears on her body when we see her as a woman again. Maybe she stores it inside the snake.]
"Over time she will not be able to transform back. She will be forever trapped in the body of a snake."
Then Creedence sets loose some noisy magical beasts to create chaos in the carnival tent. Nagini rushes the bars and strikes out at Skender and the audience all run outside. In the confusion, Nagini and Creedence escape. And that's pretty much it for Nagini. We see her several times later hanging out with Creedence on rooftops looking all somber, but she doesn't say or do anything even remotely important to the plot.
We see Nagini transform into a snake one more time after she is forced into a wall by a member of the Ministery of Magic who is supposedly hunting down Grinderweld but is really working for him. But we have no idea what's going on with Nagini. It looks like she is being attacked by her snake self and held prisoner in the wall, but we don't know why. I assume she has some powers that the double agent wants to avoid. Later Nagini is back in human form with no explanation. (There is very little exposition and few explanations in this movie. Characters are introduced then they do very little.)
But at least we know what becomes of Nagini in the future. This movie is set in 1927, but the Harry Potter movies take place much later in time. In those movies Nagini's curse has forced her to change into a snake permanently, and she has become the pet snake of the main villain Voldemort. She shows up in Harry Potter and the Deathly Hallows: Part 1 and Part 2.
According to IMDB, J.K. Rowling said that the character of Nagini was inspired by folklore from Indonesia.
I wonder if Rowling is a fan of the Asian Snake-Woman movies.