An extremely detailed 2018 Waluigi render shows that the "Γ" emblem on his hat is a sticker, as a corner is peeling off. This suggests that unlike Mario, Luigi and Wario, who have tailored caps, Waluigi was only able to afford a cap with a blank emblem that he customized himself. pic.twitter.com/sGFtoe38Bp— Supper Mario Broth (@MarioBrothBlog) September 22, 2020
Here's a bit of Waluigi lore that could have fans digging for more clues for years to come. It's certainly a point of discussion, that's for sure!
As you can see above, Nintendo released a rather high-quality piece of art for Waluigi a couple years back. If you take a very close look at that artwork, you can see that the upside-down L on Waluigi's hat actually appears to be a sticker. This is different from high-res versions of Mario, Luigi, and Wario. All three of them showcase embroidered letters on their hats when you zoom in. Why on earth would Waluigi have a sticker?!