The word “adder” in literature is used with layered meanings, serving both as a literal venomous serpent and as a symbol of insidious danger or betrayal. In medieval romances and epic narratives, the adder literally strikes—biting knights or crawling stealthily—thus foreshadowing peril and urgent, often fatal, consequences ([1], [2]). Beyond its physical presence, its venom and stealth become metaphors for treacherous human nature and deceit, where an adder’s sting suggests moral corruption or the unexpected betrayal of a trusted figure ([3], [4]). Even botanical allusions, such as comparisons to “adder’s tongue,” blend natural history with symbolic resonance, highlighting the dual nature of healing and harm imbued in the adder’s image ([5], [6]). In this way, the multifaceted use of “adder” enriches texts by evoking both the tangible threat of poison and the more abstract menace lurking within human relationships.