SHANGHAI—Remarking that the megatall skyscraper must have been drinking its milk, sources confirmed Monday that China’s Shanghai Tower had officially been named the world’s tallest building after undergoing a late growth spurt. “I guess we all figured the Shanghai Tower had already done all the growing it ever would, but then over the summer it shot up like a bean sprout!” said Shanghai Mayor Gong Zheng, explaining that everyone had come back from vacation shocked to discover the former third-tallest building was now over 2,800 feet and had surpassed Dubai’s Burj Khalifa to take the top spot. “It just seemed to happen out of nowhere. The Shanghai Tower is still a little awkward, swaying around and getting used to its new height, but you can tell it’s already starting to fill out a lot between those 80th and 115th stories. Maybe we shouldn’t have been so surprised, considering it seems to run in the family—the same thing happened to Shanghai World Financial Center, which also grew an extra 750 feet when it was around eight years old.” According to sources, Gong privately expressed concern that in addition to making the Shanghai Tower taller, the growth spurt had also made it much, much hornier.