Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is a sequel to the 1988 movie "Beetlejuice" that takes place about 35 years later, with the same director (Tim Burton) some of the same writers, the same music composer (Danny Elfman), and some of the same actors, including Michael Keaton as Beetlejuice. The first Beetlejuice also had some snakes in it, and this one does also.
Just like in the first movie, quite a few scenes take place in the world of the afterlife, where the recently-deceased, looking just as they did when they died, take a number and wait in line to find out where to go as if they're in the DMV. They also wander around through strange corridors. Thats where we see a man walking around who was apparently strangled by a large python.
After her husband Charles is killed by a shark, Delia Deetz (Catherine O'Hara) a successful artist, her daughter Lydia (Winona Ryder) and Lydia's daughter Astrid (Jenna Ortega) return to the old house in a small town where they used to live for his funeral. Delia receives a large box containing a clear terrarium with two red snakes inside. When Lydia ask her about the snakes, she says they're asps that are guaranteed harmless. Later she says whe was told they were defanged.
When her granddaughter Astrid sees the snakes, Delia explains to her that she bought the Asps to use in an ancient Egyptian ritual. (The Egyptian Queen Cleopatra killed herself with asps, so that's probably why she bought them instead of harmless snakes. It's ironic that she calls herself her husband's surviving queen, just before the asps kill her like Cleopatra):
Delia: "In ancient Egypt, a queen would perform a ceremony at the tomb of her pharaoh, using snakes, the symbol of undying love.
Astrid: "Are you sure about that?"
Delia: "Mmm-hmm"
Astrid: "We read that they were a constant threat to Ra in the underworld and represented total chaos.
Delia: "Okay, see that's why schools need more art and less reading.
Next we see the snakes in a comic scene. As she was in the first movie, Delia is still a modern visual artist who is always recording herself. We see her in the cemetary at her husband's grave, with a shark-fin grave marker, recording a performance of the ceremony she described earlier, to bless his entry into the afterworld with the supposedly harmless snakes. After she takes the snakes out of their basket and holds one in each hand in front of her face, she finds out that the snakes are still deadly when they each bite her on the neck and she keels over dead.
Next we see Delia sitting in the waiting room for the afterworld, with two large bloody bite wounds on her neck, wondering where she is and refusing to believe she's dead. She tries to talk her way out of it, but fails.
Delia does eventually escape the underworld and goes to Lydia's wedding with her fiance which Beetlejuice crashes and turns into his own wedding with Lydia. Delia sees Lydia and Astrid and explains that she is embarrassed that she died falling for a scam buying deadly snakes that were advertised as harmless.
All three of the snakes we see were created by special effects of some kind. A lot of the effects in the movie are practical effects, but there are also some CGI effects. I'm not sure how the asps were made, but other than the unnatural color, they look real enough and move fairly realistically.