text: A passage about this object was copied wholesale for a poem about Cycnus’s defeat by Heracles.
full_question: A passage about this object was copied wholesale for a poem about Cycnus’s defeat by Heracles. A field high with grain, a field being ploughed, a star map featuring Orion and Ursus Major, a city at peace, and a city at war are among the many images on this object. This object, which is described in Book 18 of a poem in the first known example of ekphrasis, is forged along with armor by Hephaestus at the request of Thetis. For 10 points, identify this defensive object that a Greek hero wears on his arm during his fight with Hector in the Iliad.
first_sentence: A passage about this object was copied wholesale for a poem about Cycnus’s defeat by Heracles.