This is an old Lakota myth as told by John Lame Deer in Lame Deer Seeker of Visions.1
I’m paraphrasing a bit here:
Iktome was an evil spiderman, a smart-ass who liked to play tricks on everyone. One day he was walking by a lake and he saw some ducks swimming around. He suddenly grew hungry for roast duck. So he stuffed his bag with a bunch of grass and then walked over to the shore. The ducks saw him and cried out, “Where are you going, Iktome?”
“I’m going to a big powwow.”
“What’s in your bag Iktome?”
“It’s full of songs which I am taking to the powwow. Good songs that you can dance to.”
The ducks begged him to sing the songs for them. The tricky spider made a big show of not wanting to do it. He said he didn’t have time for it. Finally, he pretended to give in because they were such nice ducks. “OK, I’ll sing for you, but you have to help me.”
“O yay! We’ll do whatever you want. Just tell us the rules.”
“Well, first you must form three rows. In the front row I want all the fat ones. In the middle row go all those who are neither fat nor thin. The scrawny ones go in the back row. Now you have to act out the song. Do whatever the words tell you. Here goes the first song… ‘Close your eyes and dance.'”
The ducks in their rows shut their eyes and started flapping their wings. Iktome took a big club from underneath his coat. “Sing along as loud as you can and keep your eyes shut. Whoever peeks will get blind.” He ordered them to sing so that their voices would drown out the “thump thump” of his club as he hit them over the head. One by one he went down the front row bashing the ducks. He was in the middle of the next row by the time one of the skinny ducks in the back row opened his eyes and saw what Iktome was up to.
“Holy crap! Hey wake up!”, it yelled. “Iktome is killing us all!”
The ducks that were left opened their eyes and ran away. Iktome didn’t care. He already had more duck than he could eat.