Or where can I purchase it?
Hi Judy: You can buy it at Joann's, Michaels, and I think that Home Depot carries it. Here are a couple of sites that tell you how to make it:
You can buy it at Home Depot, Walmart or Joann's Fabrics
Good old Amazon!
I've seen it at home depot.
Amazon has a lot of sets https://amzn.to/2DymzGH
Here ya go! Unicorn spit.