Clown transformation isn't entirely the bag of this site, but this particular story is full of wild transformations, weight gain, breast and ass expansion, bimbo, TG, and lots more. The plot follows a young woman who purchases a box of party favors that turns out to be much more magical and she is transformed into a giggling bimbo of a clown by a mischievous figure. Chaos ensues when her party guests arrive and she is able to use the magic of the box to transform them one by one.
Now for sale with a brand new ending (the original version of this story was never finished) exclusively on Gumroad.
https://transformansion.gumroad.com/l/partyfavors10
53 pages with dozens of fun transformations, so I hope there is something for everyone inside.