This black t-shirt features a humorous "Knock, Knock" joke, playing on the name "Doctor Who." The text is prominently displayed in white and blue. Made from what appears to be a comfortable cotton blend, this tee is perfect for fans of the iconic TV series. The classic fit makes it suitable for casual wear, whether you're attending a comic con, hanging out with friends, or simply expressing your love for Doctor Who. It's a fun and quirky addition to any wardrobe.