The Zoldyck family originates in Hunter x Hunter, the manga and anime series created by Yoshihiro Togashi, where they are feared as the world's most deadly assassins living on Kukuroo Mountain. Killua Zoldyck, one of the main characters, brought the name to a wider audience as fans followed his escape from the family business. Clips referencing the family spread through anime TikTok, YouTube edits and soundboards, where the short name drop became shorthand for elite, emotionless killers and dark character energy.