Name Source Type Y5 Adventure Time: Distant Lands Rabbit-like humanoid Yacatisma Church of the SubGenius Yag-Kosha Robert E. Howard's The Tower of the Elephant Humanoid elephant Yaetuans Christan Clines's The Yaetuan Sagas Six limbed intelligent speciesYahgMass Effect Apex predator species. Tendency to be xenophobic; one individual held the position of Shadow Broker. Yanme'e Halo Yautja Predator Humanoid. Also known as Predators. They are a warrior race that hunts down other sentient races for sport, but follow a code of honor and deeply respect those who manage to defeat one of their own in combat. Yariru Vampire Idol Vampire-humanoids Yazirian Star Frontiers Ape-like humanoid glider Yeerks K. A. Applegate's Animorphs Slug-like parasites. They need a host to see, walk, and communicate, and are the main antagonists of the Animorphs series, intent on enslaving other species. Yehat Star Control Pterodactyl-like Yengi-Tat Hack RUN Earth-occupying aliens in secret Yeti Doctor Who Yilane West of Eden series by Harry Harrison Yip-Yips Sesame Street Yliis 2300 AD Yolkians Jimmy Neutron Gooey Slug-like aliens with egg shaped suits. Yomingans Schlock Mercenary Yor Galactic Civilizations Yorn Star Control 3 Ythrian Poul Anderson's Technic History Eagle-like aliens Yridian Star Trek Yugopotamians The Fairly OddParents Squid-like aliens with dome-covered brains. Yuuzhan Vong Star Wars Humanoid