The role of transposable elements in eukaryotic biology is enigmatic. Converse to what is well established for a number of transposons found in prokaryote species that include within them genes providing benefits to their new hosts, to date transposons in eukaryotes have historically been considered selfish pieces of DNA, and any benefits conferred an indirect consequence of either inadvertent insertion or recombination. The Starships are large genetic regions recently found in fungi that have been proposed as host-beneficial transposons. This research explores Starships in Paecilomyces species. First, we show that these are indeed active transposons and define the key enzyme, a putative tyrosine recombinase, required for their movement. Second, we show the elements have jumped between fungal species. Third, we demonstrate their rapid death through the process of repeat induced point mutation. The Starships are especially prevalent in ascomycete fungi where they confer different benefits to their hosts. This study now shows that transposable elements are directly beneficial in at least some eukaryotic organisms, and may well have shaped extensively the transfer of useful traits across the fungi.