Wants to Use Wally the Green Monster™ on Onesie®

"I am not a monster."

Dear Rich: My friend at work commissioned me to make a onesie with "Wally the Green Monster" the Red Sox mascot. Is this a copyright infringement? Surprisingly, you're more likely to get hassled over your use of "onesie" than Wally. That's because the term ONESIE ("an infant's one-piece close-fitting lightweight garment, usually having sleeves but leaving the legs uncovered and fastening with snaps"), is a registered trademark of the Gerber company (which has gone after some Etsy-ites as well as the owners of "OneZ"). Considering the widespread non-Gerber use of the term, it's possible that Gerber's ONESIE is headed towards genericide (much like Raisin Bran and Escalator) but we won't know the likelihood of that until someone with deep pockets is willing to take on Gerber's legal department. Till then, crafters and Etsy-ites should be aware that Gerber's lawyers are on the prowl. If you want to stay low on Gerber's radar, you might want to do what retailers such as The Gap do ... they use the term "bodysuit" with their products but apparently buy keywords for "onesie" in order to direct consumers to their websites.
Right, you had a question about Wally. Team mascots are trademarks (or trade dress) of sports teams. They may be federally registered (as is Wally the Green Monster) but registration is not required to claim trademark rights. In any case, we don't imagine you'll be hearing from Red Sox lawyers over your onesie, as professional teams tend to aim their guns at offensive uses or high-profile merchandisers.