Pennywise distorts himself and moves in unnatural ways. Some of this is quite comical, however.
There are many jumpscares.
There is a scene where Pennywise's mouth and hand is ripped open showing Mantis or Werewolf like skin
Bill's main priority throughout the movie is that he'll find Georgie alive and well, despite both his father and Richie telling him otherwise, many scenes involving this can be emotional.
It transforms into a homeless man with Leprosy. His nose is missing, his eyes are red, his skin is covered in grotesque rashes, and there is a sticky substance leaking from his mouth. one of his legs in incredibly slim, while the other leg is about as wide as an elephant's leg.
Pennywise can unhinge its jaw like a snake, it's disturbing to watch.
Penny wise is seen opening his mouth very wide there are also many sharp teeth in his mouth along with a glowing light in the back of his throat. Can be frightening to some younger viewers.
The opening scene especially is about as frightening and disturbing as it gets, especially since it involves a young child.
A girl is blasted in the face with gallons of blood, frightening and a bit intense.
The Flute Lady, is a scary looking thing. It might scare young viewers.
Ending of the movie kinda uses the effect of fake nostalgia. That's why it's so emotional.
MA15+ ( Strong Horror Themes & Violence )
Pennywise's appearance may be disturbing to some viewers, especially for people who have a fear of clowns.