Misjudged in donkey's clothing

Traditional in his ways, he carries his burden, dutiful like a mule

A mule who thinks itself a thoroughbred, when others see a nag

Loyal to its masters, experience in its abundance, disinterested in the antics of others
Yet cometh the day when the burden is relieved, to a replacement full of noise

Then led towards the gate, shut firmly behind, pastures new.