This is a Japanese snack known as Takoyaki. It is filled with chopped octopus, tempura flakes, pickled ginger, and green onions, made of wheat flour based batter. The texture of this is that it is slightly crispy on the outside and it is soft and creamy in the inside, topped with takoyaki sauce, mayonnaise, and bonito flakes. The bonito flakes gives it a nice savory flavor. Takoyaki is usually served in 6 to 8 balls because it is not served as a meal but it will fill you up since the batter is made of wheat flour. You should definitely try this when you have the chance to.