Red Super Mario Tee T-shirt.  It is marked XXL/2XG(18).  I measured it, and it appears to be equivalent to a men's size small/medium.  Approximate Measurements from arm pit to arm pit =18 1/2" and length as measured in the back = 23".  Excellent pre-owned condition.  "2020 Nintendo".  Cotton blend, RN#77272.  Thank you for looking.