Video shot by the boy's mother shows a dozen or so men in the Furn El Chebbak neighborhood of Beirut, the Lebanese capital, belting out the earworm tune that has bewitched children and bedeviled parents around the globe.
Robin, the toddler, looks on as protesters carrying Lebanese flags surround the car and perform the song's signature clap.
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One of the men in the video, Elie-joe Nehme, told NBC News via Facebook Messenger that he and other protesters were yelling and clapping as they marched alongside some cars during a road closure on Saturday. Then a woman nearby told them to be quiet because of the noise bothering baby Robin.
"So we sang 'Baby Shark' to make him happy," said Nehme, 22.
The boy's mother, Eliane Jabbour, told NBC News her 15-month-old was "surprised but not afraid" to hear a rowdy rendition.