Get a clown

If you need a birthday clown, you look in the Yellow Pages for one.
On the other hand, if you need a demon clown, you draw a pentagram with silly string and sacrifice a balloon animal.
It’s not easy spraying a decent pentagram with that stuff, but with a little practice and a steady hand you’ll have your clown army of darkness.
Why you want a clown army of darkness, I won’t ask. I just teach these summoning spells. What they’re used for, it’s not my problem.
Here’s a can of silly string, a balloon, and my spellbook.
Good luck.