Droch
Drochs are an existing species of parasites from Legends.[1]
At some point during or before 3 ABY, Seti Ashgad hatched a plan to send drochs to Palpatine's resort world of Byss, as revenge on Palpatine for having exiled him to Nam Chorios. Ashgad had Melia Keefe and her children infected with drochs when they departed from nearby Pedducis Chorios, having won tickets to Byss in the Imperial Lottery. However, Ashgad's plan failed, and the Keefes ended up dying in the Hoth system after a series of increasingly erratic hyperspace jumps as a result of the droch infection.[2]