Leap Day comes only once ever four years, and Marvel Heroes is celebrating by giving out free frogs and gratuitous amounts of XP. And by gratuitous, we mean 229% more throughout the rest of the day! Add that on top of the regular Monday Midtown Madness bonus and you might be able to level up a few of your favorite heroes. If you don’t have much time to play, you still may want to log in long enough to nab your very own Throg pet, a miniature version of the Thor himself — if Thor were an amphibian, that is.
Source: Official site