nuko (shoujo shuumatsu ryokou)
A creature encountered by Chito and Yuuri in Shoujo Shuumatsu Ryokou. They wrongly believe it to be a cat and name it "Nuko" after a mis-remembering of the word "Neko". It is incapable of producing any sounds but communicates through a frequency that can be heard on the radio the girls find, and it slowly learns how to speak their language. It feeds on things of no apparent nutritional value, like metal.