St. Patrick's Day is one of the most popular holidays of the year and Darth Vader is one of the most popular movie villains of all time. Now, the two come together on this Shamrock Vader Helmet Star Wars t-shirt! This shirt shows the unmistakable shape of Darth Vader's menacing helmet made out of green shamrocks. You can finally let everyone know that you are a fan Lord Vader while you celebrate this St. Patrick's Day.