WW Used Game Shenanigans?!

[Camillion]

I went to Disk Replay and bought a used copy of Wild World with a grin on my face. Like I always do, I checked who the guy that had it before had in his town. The house was fully developed although all the villagers were giving tutorials, and here's the odd thing... I met a FEMALE SNOOTY SNAKE AND CRANKY TWIGGY. It freaked me out so much that I automatically reset in fear that the game was going plain corrupt but upon resetting a few times things are looking rather normal. I'm looking to reset for Snake just to see, though. Would it be safe to keep a cart like this or should it be returned?