Wander through the world of Nintendo's EarthBound for the Super NES and you'll end up talking to hundreds of people. Every city, village, and dark underworld is packed with folks all too eager to speak with hero Ness and his band of adventurers. Some of these talkative characters fell victim to programming errors, however, and fail to appear during the course of the game. Nothing vital to the quest was lost, but since it's well documented just how rabid EarthBound fans can be, you probably shouldn't be too surprised that those missing characters have been hacked back into the game where possible. EarthBound Central explains.
[T]here’s a whole load of unused text in EarthBound. Some of it is just loose scraps that isn’t fully implemented into the game anymore, but there are some lines of text that work perfectly except for simple programming bugs that prevent the NPCs from appearing. Using the power of ROM hacking, we can see how they were meant to show up. The bug in those instances were simple event flag settings being incorrectly set. It looks like Threed was probably one of the first few big areas that was developed in the game, so maybe that’s why these bugs snuck in.
There are additional bits of dialog summarized in the original article, so be sure to check it out to get the whole story. Once again, game archeologists have sifted through the dust to find a neat fossil. Consider this another artifact to display in the museum.