Many people said frightening a child was not appropriate NT

Yes, child psychology and development experts (such as NAEYC) agree that intentionally scaring children is generally inappropriate.

5 Ways to Support Your Kids During Scary Times - Parent Cue

The most important thing is to ᴀssess each child’s individual reaction to frightening images or situations. If you are considering exposing your child to sensational elements, please share more information so I can better ᴀssist you:

What is the child’s age? What specific situation are you referring to (e.g., watching a movie, listening to a story, or playing a prank)? What is the child’s current reaction to the frightening event (crying, avoidance, or curiosity)?