Candroidan Hookworm
this parasite was particularly dangerous, because its genetic structure allowed it to support viruses that were specific to humans. These hookworms burrowed into their hosts and lodged themselves in the circulatory system, and could not be removed without killing the host. When they reproduce, the hookworms "shed" any viruses it carried, dispersing them into the host's blood supply. For this reason, saboteurs and assassins liked to infect these hookworms with plagues and set them loose in human-inhabited areas. A swarm these creatures was known to have infected Calif City, on Dentaal, with a strain of Candroidan Plague, depopulating the city in just three weeks.