beast of burden

/B IY1 S T AH1 V B ER1 D AH0 N/
noun
  1. 1

    A draught animal, such as a donkey, mule, llama, camel, horse or ox, that carries or pulls a load for the benefit of a human.

  2. 2

    (by extension) Any domesticated animal trained to perform tasks for humans, such as a herding dog or trained falcon.

Source: https://en.wiktionary.org/wiki/beast%20of%20burden