Serpents, also called slitherettes or snakes, were long creatures that lacked limbs. They got around either by wrapping themselves around objects or by moving sideways across the terrain. Some serpents possessed venom.
During the Great Sith War, at the Battle of Coruscant, green serpents launched an assault on the Republic command center just before Aleema Keto and Ulic Qel-Droma moved forward.
Asajj Ventress, while working as a bounty hunter in the Clone Wars, sported a black serpent on her shoulder piece.