Google AI Studio by mistake let me generate this image of mario hanged, I know it was by mistake because further attempts always throwed unspecific legal reasons, even if nothing that could be perceived as violent was included, I think I am gonna put it on a t-shirt soon, if for any reason someone here wants it here it is: https://i.imgur.com/j4ebG2D.png
I think this falls under the fair use doctrine for being a satiric piece (says "nintendont" instead of nintendo) but you never know these days.
As the link shows, if you would put it on a t-shirt, you can absolutely expect to hear from Nintendo's lawyers, so the question will just be whether you have the time to put up a fight.
Oh, Nintendo can't technically win a lawsuit against you if you make something for personal use, but they absolutely can and will try and ruin you financially before it sees a courtroom.
I think this falls under the fair use doctrine for being a satiric piece (says "nintendont" instead of nintendo) but you never know these days.