That's Narutoad.
People often question why it was chosen for Smash, and that's because GF designed it to appeal to kids and become the most popular. Not only that, but they also gave it an ability and move-pool that shames the other starters, making people who like powerful overused pokemon like it too.
GF knew it would get popular, and by letting Nintendo put it in Smash they are hoping to make another Lucario.
