The Aztec death whistle was most likely used as a spiritual conduit of sorts during religious practices and it's also widely believed that it was used as a form of psychological warfare. It was used to terrify Aztec and pre-Columbian foes on the battle field.
An Amphiptere is a hybrid from European heraldry, part snake and part bird or bat. Heraldry is a broad term, encompassing the design, display, and study of armory or armor, as well as related disciplines, such as vexillology (flag design,) together with the study of ceremony, rank, and pedigree. Throughout Europe, the amphiptere was widely feared, so all who displayed it on their coat of arms would be perceived as particularly fearsome in battle.