‘跟屁虫’ literally means ‘a bug that follows the buttocks’ — a vivid, humorous metaphor for someone who constantly tags along behind another person, mimicking their actions or words without independent thought. The character 跟 (gēn) means ‘to follow’, 屁 (pì) refers to ‘butt’ or ‘fart’ (here used idiomatically to suggest something trivial or absurd), and 虫 (chóng) means ‘insect’ or ‘bug’, adding a playful, slightly derogatory tone. It’s often used affectionately among children or teasingly among friends, but can carry mild criticism when describing overly dependent or unoriginal behavior.

This term is informal and commonly heard in spoken Chinese, especially in family or school settings. It emphasizes persistent, uncritical imitation rather than simple companionship — a ‘跟屁虫’ doesn’t just accompany you; they echo your choices, repeat your phrases, and rarely initiate anything on their own. Though rooted in childish behavior, adults may use it lightheartedly to describe colleagues or friends who habitually agree or copy without reflection.