The Purzithroan Vagabonds came from the Ambient Expanse. They were a gang of ruthless pirates who often grafted cybernetic parts onto their damaged bodies, giving them greater strength. Their "crest" was a half cybernetic head.
The Purzithroan Vagabonds were a largely undisciplined bunch who, for a while, profited by stealing seeds held in storage in the Terran Seed Vault in Norway on a solar-ravaged Earth of the future. They fled the vault after being scared off by holographic images believed to be ghosts, and warnings created by the Eleventh Doctor and Amy Pond from the control room in the Vault. (COMIC: Pirates of the Seven Seeds)