‘哇呜’ is an expressive interjection used to convey mock fear, sudden surprise, or playful alarm—like a cartoonish ‘Eep!’ or ‘Whoa!’ It combines two onomatopoeic characters: 哇 (wā), often signaling shock or awe, and 呜 (wū), which mimics a soft wail or whimper. Together, they form a lighthearted, exaggerated sound effect rather than a literal description of emotion.

This expression is commonly used in informal spoken Chinese, especially by children or in animated storytelling, role-play, or humorous online communication. It’s not appropriate for formal writing or serious contexts. While both characters individually can appear in other expressions (e.g., 哇 for excitement, 呜 for crying), their pairing as ‘哇呜’ is fixed and functions as a single unit—never split or modified. Think of it as the Chinese equivalent of a stylized gasp with a tiny whimper attached.