"The rest is easy. Watch one change sometime and see how slick he does it. He kind of softens his skull, and part of it flows forward and part of it flows back. Then he lets his eyes roll around to the sides of his head. He sharpens his muzzle and does all the other little things. Then he goes down on all fours just like he was unhinging himself. He begins to shiver: that's one way he brings the hair out of his hide. After that he lacks just one thing for him to be a total wolf."
Well, someone had to ask it.
"What's the one thing he needs to make himself into a total wolf," Pidgeon asked, "after he has gone down on all fours and shivered his hair to the outside of his hide?"
"The tail," said Corbey, and licked his lips. "It sounds like a cork popping when he brings it out. The tail's the last thing to go back in too. And after he changes quite a few times, man to wolf and wolf to man, why his tail gets where it won't go all the ways back in anymore. I maintain, Sheriff, that there's a way to put this knowledge to test."
What was Corbey getting at? There was dark lightning bouncing around that store. There was musky excitement beginning to rise, and the feeling got riper by the minute. Something was brewing, and it was these fellows' kind of thing.
"Men, this becomes a community effort," Corbey was crowing. "Sheriff, we got to get every man-jack in the neighborhood together and make them strip. Sheriff, one of those men is going to have a tail!"
-R. A. Lafferty, 'Three Shadows of the Wolf' (1975)