Changes

Not only is this a rhyme (and a great one, at that), there’s a lot of repetition in it, and a momentum than never stops building. As some things are dropped and others collected, Yak’s load changes one item at a time, like a long game of 'Grandmother’s basket', so you have to remember what’s on there already. There’s a counting element too :

''And hanging on grumpily, one Captain Quack!''