What did the duck do to satisfy the kangaroo?

The Duck wanted to see the world and felt bored sitting in his pond. Therefore, he tries to persuade the Kangaroo to carry him along while on a hopping spree moving across lands and seas. The Duck describes his life in the "nasty" pond as boring and stagnant where he wearily has to pass time sitting on the rocks.?The kangaroo told the duck that he was willing to take him on a ride but there was a problem that since the duck's feet were always cold and wet, it might give the kangaroo the disease of rheumatism. ?