I wouldn't know, though clowns have varied both in costume and performance.
There are various traditions in costume and performance for clowns. I guess you're talking about the Stephen King movie, It?
I am so scared of clowns. What can you tell me about them? I can tell you that they're comics who use slapstick and other physical comedy. Maybe it is the movie It that caused my fears.
Clowns have a varied tradition with significant variations in costume and performance.