And then you delete it.
According to sleuths on r/InternetMysteries (which has tried and failed several times to solve this), the original @Skuddbutt was a low-follower account run by a digital artist from Leeds, England. The story goes that this user began suffixing "skuddbutt" to random tweets as a verbal tic. skuddbutt twitter
Welcome to the mystery.
If you have spent any time scrolling through the underbelly of niche Twitter (X) communities—particularly those revolving around surreal memes, unexplained screengrabs, or crypto-linguistic chaos—you may have stumbled upon a phrase that seems to defy search engines: "skuddbutt twitter." And then you delete it