Have always made goofy faces to communicate with other TMs if I can’t say something out loud (with a guest, or thing said might be viewed as inappropriate, etc.) and by now I’ve conditioned most of the team to do it back, including the upper leadership.
Have (harmlessly) pranked people before, including ETL-AP, APTL, and TPS guys. Usually just goofy stuff to get back at them for previous shenanigans.
Used to attach any unidentifiable blind bag toys we found laying around without packaging to the electronic registers and receipt printers using velcro dots. Kiddos shopping got a kick outta that, some parents, too.