Rugosan King coral was a species of massive green coral that thrived within the coral forests located on the moon named Rugosa. During the period of the Clone Wars, King Katuunko, the Toydarian ruler, planned a meeting with Jedi grandmaster Yoda. This meeting was to take place atop a frond of a Rugosan King coral, with the purpose of discussing whether his homeworld, Toydaria, would join the Galactic Republic. However, upon landing his starship on the coral structure, he was met not by Yoda, but by Separatist operative Asajj Ventress, who presented a hologram of Count Dooku suggesting Toydaria's allegiance should instead be with the Separatists.
After Katuunko made contact with Yoda, an agreement was reached: if the Jedi could arrive at the Rugosan King coral before the sun set, Toydaria would align with the Republic. Conversely, should they fail to arrive in time, Toydaria would join the Separatists. Ultimately, Yoda, accompanied by a group of clone troopers, successfully reached the coral before the deadline. Ventress attempted to eliminate them by triggering Katuunko's starship to explode, causing damage to the King Rugosan coral and sending debris towards Yoda and his allies. Yoda employed the Force to prevent the coral and starship fragments from crushing his allies, which gave Ventress the opportunity to escape.
The Rugosan King coral made its debut in "Ambush," which was the inaugural episode of the first season of the Star Wars: The Clone Wars animated series. It was initially broadcast on October 3, 2008. The coral's name was officially established later, in the 2017 reference book titled Star Wars: The Visual Encyclopedia.