Should i rent a horse for halloween?

I want to be a cowgirl for Halloween. I think it would be really cool if i rent a pony (slow and non spooky) and ride it on halloween. i have a horse, but she is very fast and spooks easily and doesnt do good on the road so thats out of the question. Do you know if this is safe? If you think i should do this, do you know any places that I could do this? PLEASE answer soon!