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The humphead wrasse is also called the Napoleon wrasse because the bump on its head resembles the two-pointed hat worn by French Emperor Napoleon.

Notes on verification

Widely repeated folk-etymology across multiple independent aquarium, dive, and conservation sources, but it's an informal naming origin not backed by a definitive linguistic/historical authority; some minor variation in framing exists (e.g., Hakai Magazine's 'forelock' explanation).

Sources