Kuvu
It's said that life takes many forms. A character in a late 20th-century video entertainment put it as "life finds a way." As humanity has ventured out into the galaxy¸ this axiom has proven true again and again. Of most interest - and wonder - is that life finds a way to bring sapient life into existence.
When early explorers landed on a world not too far from the interstellar government's core¸ they discovered a world covered not in plant life¸ but in lush fungal forms both familiar and unfamiliar. Every conceivable niche of the planet's environment contained a fungal analogue of plant or animal species found on other worlds. But the explorers received the biggest shock when they encountered the alpha species of the planet: a native sapient fungiform. The human explorers called the species Kuvu (Swahili for "mushroom.") After a few missteps due to disparate means of communication¸ humans and Kuvu learned to exchange information and work together.
Lifeform Reading: Kuvu is for 2D6 science fiction games such as Cepheus Engine and The Original Science Fiction Roleplaying Game (OSFRPG)¸ although it's usable with other systems with a little work. The Referee¸ as always¸ is the final judge as to whether the supplement is useful for his or her campaign.