running crab - fashion up the stony river bank , over the pathways into the shadowy forest , the crab at last found the monkey taking an afternoon nap in his favorite pine - tree , with his tail curled tight around a branch to prevent him from falling off in his dreams . he was soon wide awake , however , when he heard himself called , and eagerly listening to what the crab told him . when he heard that the seed which he had long ago exchanged for a rice - dumpling had grown into a tree and was now bearing good fruit , he was delighted , for he at once devised a cunning plan which would give him all the persimmons for himself . he consented to go with the crab to pick the fruit for him . when they both reached the spot , the monkey was astonished to see what a fine tree had sprung from the seed , and with what a number of ripe persimmons the branches were loaded . he quickly climbed the tree and began to pluck and eat , as fast as he could , one persimmon after another . each time he chose the best and ripest he could find , and went on eating till he could eat no more . not one would he give to the poor hungry crab waiting below , and when he had finished there was little but the hard , unripe fruit left . 
he wanted to trick the crab .
why did the monkey agree to help the crab ?
why did the monkey agree to help the crab ?