Irnstad was a Dragon Rider that lived before Galbatorix's reign. He was one of only four beings to slay a Shade and live to tell the tale, the other three being Laetrí the elf, Eragon and Arya. Judging solely from the composition and sound of the name, one could suppose that Irnstad was a human male. However, Irnstad's race and gender are never mentioned in the books.