equator, it is accessible from May through Animal Crossing Bells September.
December is close to the corner, which implies new fish, bugs and ocean animals for both Northern and Southern Hemisphere major parts in Animal Crossing: New Horizons. There won't be huge loads of augmentations to the Critterpedia on northern islands, however southern islands will see a convergence of new critters to get.
Here are largely the new fish, bugs and Buy Animal Crossing Bells remote ocean animals coming to New Horizons in December, just as where to discover them, when they come out and the amount they sell for.