I was trying to recall just how early "Big N" was a nickname for Nintendo, thinking it must have predated the Nintendo 64, but it took a bit of digging to find anything concrete:
My naive first thought was "Captain N: The Game Master" but that wasn't quite "Big N." But it was fun to visit a bunch of old Nintendo-related articles.
It's funny to me because I've never heard anyone refer to Nintendo as "Big N" there's a handful of other things referred to as Big N, Nintendo is not one of them.
I replied in another thread [1] but this was the earliest thing I could find in online resources, but maybe your recollection would lead to something earlier:
Big N, really?