M&M's is debuting a new seasonal flavor this fall called Boo-terscotch that you likely won't be surprised to hear is supposed to taste like butterscotch. But it turns out these new M&M's might taste like something else to Harry Potter fans.According to Bustle, those who have tasted the newest flavor, which is white chocolate-infused with butterscotch, are saying it tastes like Butterbeer. Which is, of course, the popular wizarding beverage Harry and his friends drink.While Butterbeer isn't exactly real, fans have been able to taste it for themselves at the Wizarding World Of Harry Potter in Orlando.The Boo-terscotch flavor is currently being sold at M&M's World, but will be available for a limited time this fall at Target.M&M's also announced they will be releasing three other flavors this fall. They include candy corn, pecan pie and Harvest, which will include all four seasonal flavors as well as the classic peanut and peanut butter.You may want to invest in an invisibility cloak though to make sure you get these new M&M's before they're all gone.