Best Answer: Xanclomys: a small mammal from the Paleocene of North America. Xanthareel: yellow eel. Xantis: a yak. Xantus: a bird. Xantus murrelet: a small seabird found in the California Current system in the Pacific Ocean.Xantusiidae: family of night lizards.nimals beginning with the letter X: Xanclomys: a small mammal from the Paleocene of North America. Xanthareel: yellow eel. Xantis: a yak. Xantus: a bird. Xantus murrelet: a small seabird found in the California Current system in the Pacific Ocean. Xantusiidae: family of night lizards. Xeme: an artic fork-tailed gull.