In the first movie there is only a snake at the beginning of the movie when Harry goes to the zoo. Then we can see depictions of snakes in the slytherin banners. Lots of snakes in the other movies though.

crowley was originally the snake in the garden of eden

Yellow Fever has snakes. Also season 14 Jack gets a snake and Dean is afraid of it

The cherub's mating ritual is to turn into giant snakes and battle. Some Denizens resemble snakes.

They don’t have any arms!

There are numerous snakes, but a statue of one is used as a jump scare in a box opened by Jaime and Cersei.

In an episode where Peralta and Holt are relocated to Florida, Peralta impersonates an exterminator and has to remove snakes from an elementary school. The snakes are shown and Peralta is visibly and audibly frightened as he removes them.

There are anthropomorphic snakes.

But only on the southside.~

Coven

A rattlesnake in a drainpipe the family crawls through.

when theyre getting their spirit animals there is a giant python, i'd skip this part if youre uncomfortable with snakes.

a character is bitten by a snake and dies from an allergic reaction

You won’t encounter them often. Maybe once or twice if you’re actively looking for them.

In part 5 a character dies after his tongue is bitten by a venomous snake.

Part 1 has a villain with snakes for a face

A horse spooks at the sight of a snake in S2:E5, the camera zooms in on a snake and you hear it hissing and see it slithering away

The Baudelaires live in the home of a herpetologist who owns countless snakes (S1E3 and S1E4). A large snake is shown approaching the Baudelaires (S3E7).

BIG snake monster

A snake kills another animal. Mostly offscreen but enough is shown and described that it is upsetting.

crybaby’s bully wraps a snake around her neck while sleeping

Beetlejuice turns into a giant snake monster and attacks and injures at least one person in one of the more genuinely frightening segments of the movie. (Injury is done by falling, not snakebite.) Giant, snake-like creatures called sandworms appear, and one swallows a character whole at the end. Nothing graphic or bloody.

Honeyfern gets bitten by a snake and dies, along with Frecklewish (but this wasn't really an accident like Honeyfern's, rather another cat beckons a snake to kill her)

The villain has many small animal minions or familiars, including snakes. There is also a large boa constrictor-like snake that lives in Halloween Town and has an indiscriminate appetite.

In one episode of season 2, someone dances with a snake to the song I'm a slave 4 U

There is a very minor character with snake hair.

One episode has the villain use a snake to scare a main character helping out in a fashion-type event.

We're talking walls of snakes. Huge, writhing masses of snakes. I've read that 5000 live snakes were used in the production.

a real big one