Other than "puke" being the subject of most of the stickers, they remind me of the ones Topps did for Trump's first 100 days in office. In other words, most of them look like they were Photoshopped rather than hand drawn.
Besides the t-shirts, they have stickers too. I noticed that they all have a thick border of some color. Didn't Topps sue Silly Supermarkets for copyright infringement on their thick borders? At $2.50 a poop, er pop, that's $140 to get 'em all...but with the 25% off for buying 4 or more!, it's only $105...and you qualify for free shipping since it's over $80.
Some of the descriptions even mention Wacky Packages:
https://www.teepublic.com/sticker/34107185-pukey-products-37-tufted-big-boy-shrimp-scented-bePukey Products 37 “Tufted Big Boy” shrimp scented beard spray Sticker
Wacky Packages Sticker
Designed and Sold by Popoffthepage
They have magnets too, in two different sizes for $4.50 and $5.50. I noticed that the stickers all had a drop down list for size, but the ones I looked at only had one size.