The pallaskean was a type of sea serpent species found inhabiting the oceans of the planet known as Ahch-To.
During her training sessions with Luke Skywalker on Ahch-To, Rey inadvertently discovered a pallaskean's nesting site, which provoked the mother pallaskean to launch an assault. Chewbacca, along with Rey and Luke, intervened quickly to reposition the rock covering the eggs. Once the creature had calmed down, Rey acknowledged the lesson she had learned about acting impulsively.
The pallaskean made its debut in the comic story titled "Life Lessons," penned by Cavan Scott with illustrations by Derek Charm. It was released on September 25, 2019 in Star Wars Adventures (2017) 26 by IDW Publishing. Scott drew inspiration for the pallaskean's name from the Panna dragon, a creature featured in The Story of the Faithful Wookiee, an animated portion of the 1978 movie The Star Wars Holiday Special.