Hope these are close enough in spirit to qualify...
I can, as if I were playing drums, tap my feet and hands and nod my head and wink an eye etc. etc. all at different rates, not randomly, but sort of like a binary divide chain where each action is 1/2 as often as the proceeding one. Not easy for non-drummers and a fair percentage of drummers.
In SO CAL with many VHF and UHF repeaters to talk over (ham radio) You frequently ID yourself to other participants with your ham call sign, often with non-standard (usually at least moderately humorous) phonetics.
I used to ask folks if they would like to know my call sign and when they said yes I would say N6 Are You Ready? They would usually say yes, go ahead. I would then either say again, Are You Ready or some variation on the theme, repeated until 87% of the humor was wrung out. My ham call is of course N6AYR (Are You Ready).
At Lowes or the super market or wherever some cashier will say, "I can help you over here, sir", to which I frequently reply, "no thanks, I can make it on my own, without help."
Like the man said, "A mind is a terrible thing to lose."
I also do card tricks. Learned a few from a college room mate who was an aspiring but minor professional magician. He used to really hate it when he would "do" a trick for me and then I would "do" it for him, having deduced the "trick" in one viewing. The upset was added to because those guys pay good bucks to buy some of their material.
Patrick