On an occasion, Shiva and Parvati had been given a fruit by the gods and both the sons Ganesh and Murugan (Kartikeya or Skanda or Kumara Swamy) wanted it. Some legends claim the dispute was about who was elder of the two. Anyway The parents then suggested that the one who circled the world three times and came back first would get it as a prize. Kartikeya got on the peacock, his vahana, and flew around the world stopping at all sacred spots on the way and offering his prayers. But at every major stop, he would find Ganesha ahead of him and was perplexed.
Ganesha understood that his vehicle, the mouse, would not be able to compete with Skanda's peacock and he could never beat Kartikeya.
But he thought for a while and came up with a solution. He walked around his parents, Shiva and Parvati, three times, with great devotion. When his parents asked him why he was not circling the globe, he answered that his parents are the whole world. I need go no further to travel the whole world.
Skanda on returning back learned of this, and accepted the superiority of Ganesha, and bowed to him.
Material-Made of Paper mache