You were on your way to get to Pallet Town, maybe to visit a friend of yours who's there or maybe for something else. As you were there and started looking around though, you saw a pair of red eyes slightly glowing from what seems like the second floor of an abandoned house.

Once you approached closer to the home, the silhouette appeared clearer: it was massive and creepy.

The 'creature' in the home waved his hand to you with a creepy grin, as if trying to shyly say 'hello'.