Pym

 was the captain of the pirate ship Parliament of Rats. He and his crew had been horribly mutated due to the time fractures that ravaged Lethe. His crew boarded the Lung of Heaven in search of its captain, Katr Korzen. Her crew surrendered to the pirates but she hid with the Fifth Doctor. When Pym boarded the Lung, Korzen came out of hiding and killed him. (PROSE: The Parliament of Rats)