Xerus, Xantus’s hummingbird, Xenops, Xoloitzcuintli, X-ray tetra, Xingu river ray, Xeme, Xantic sargo, Xingu pleco, […]

Yak, yellow baboon, yellow mongoose, yellowhammer, yellow-eyed penguin, yellowfin tuna, yellowtail snapper, yabby, yacare caiman, […]

Zebra, zebu, zorilla, zebra finch, zigzag salamander, zipper loach, zokor, zonkey, zander, and zebra shark […]