The exact origin of this clip is undocumented: it arrived on the soundboard under a user-style filename with no credited show, game or creator attached, which is common for short reaction exclamations that circulate freely. One-syllable surprise sounds like this 'wao' travel well because they need no translation and fit any language's edits. It survives as a utility reaction, the kind of clip editors keep in a folder of quick emotional punctuation for wins, reveals and comic beats, valued for its speed rather than any backstory.