Parasite

Parasites were lifeforms that attached themselves and leeched off another to survive. Rock warts, phidna and the brain worms of Geonosis were examples of parasites. The word "parasite" could also be used as an insult, such as towards pirates and other thieves.

After the existence of Order 66 was nearly exposed late in the Clone Wars, Supreme Chancellor Sheev Palpatine, secretly the Dark Lord of the Sith, covered up the incident in part by making up a spurious Ringo Vindan parasite which had supposedly caused Tup and Fives, two clone troopers involved in the incident, to go insane, a story that the two clones' deaths made it hard to disprove.

The saava was a species of serpentine parasitic carnivorous plant native to Kashyyyk that would creep toward prey and latch onto it with its flower-like heads, then proceeding to feed on the still-living host for months or years. The Jedi Padawan Cal Kestis survived encounters with saava plants during his mission to Kashyyyk.

Text and facts from the “Parasite” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.