inexplicable mob noun a large crowd that materialises in a public place to perform a scripted action for several minutes before dissolving US
"There seems to be something inherently political about an inexplicable mob," he said. — Wired.com, 5 July 2003
Well, many of us were milling around waiting for it to be exactly 7:27 and sort of steeling glances at each other and wondering who was there for this inexplicable mob[.] — AllThingsConsidered(National PublicRadio), 20 June 2003