What do hundreds of furry, little animals have to do with the Las Vegas Strip’s newest resort? Apparently nothing, but they piqued viewer curiosity during the Cosmopolitan of Las Vegas’ first commercial earlier this week — and that’s exactly what the resort wanted. Just two months before its opening, the $3.9 billion hotel-casino debuted its curious and provocative TV ad during the season finale of “Mad Men” on AMC Sunday evening.