Alexander the Great used giant armor to scare enemies

When you want to thoroughly psych out your enemies, gaslighting them with oversized clothing is a genuinely elite strategy. During his retreat from India, Alexander ordered his men to bury massive, oversized breastplates and weapons in the sand. The cynical goal was to leave behind 'evidence' that his troops were literal bloodthirsty giants, making any pursuing army immediately reconsider their life choices.