Based on the idea of the straw that broke the camels back The Last Straw is the Christmas story told from the point of view of a camel who is asked to carry the gifts of the wise men.
Hoshmakaka is an old camel and his body is suffering all the aches and pains of old age but he is also an arrogant and boastful camel. He has a huge ego and so even though he is asked to carry enormous quantities of gifts for the baby king he does not give in although he does grumble under his breath the whole way.
"Why me? If these men are so wise, don't they know about my joints? My gout? My sciatica? What did you say I am to carry? How much will it weigh? Besides I have other commitments. There is a water-drinking competition in Rangal. Then I really must go to the cud-chewing convention in Beemish." In spite of these objections Hoshmakaka agrees to do as the voices have commanded. He makes the boast that he is as strong as ten horses. The young camels who walk beside Hoshmakaka on this journey to deliver rich gifts to the baby king use this boast to keep him walking.
Along the way more gifts are added including milk from some mountain goats, bags of ground corn, fine silks, two rare birds, pillars of oak, sweetmeats and pastries, jars of honey, jewels, beads, rolls of leather and twenty gallons of wine. Finally one small boy brings a tiny gift for the baby - a piece of straw for his bed.
"And with that, Hoshmakaka fell to his knees... Then from the humble manger, a tiny hand reached out and touched Hosmakaka."
This is another one of those old Christmas books. It was published in 1998 but you might be lucky and find it in a library. The illustrations and story remind me of books like The greatest treasure of Charlemagne the King by Nadia Wheatley and The Quilt makers gift by Jeff Brumbeau. Here is a page of teaching ideas.