Attachment
Among the files included in the Gigaleak, a massive 2020 content leak of internal data from Nintendo, are models associated with Dōbutsu no Mori depicting three human characters not seen in the final game: two redcoat soldiers, one tall and one short, and a middle-aged woman in an apron. These characters appear to be early versions of Copper, Booker, and Joan, respectively, which is corroborated by the fact that the woman's filename is "oba," with Joan's sleeping animation being labeled "Sleeping_Obaba" in the files for Dōbutsu no Mori.

All of this appears to indicate that special characters were originally intended to be human before being changed to unique animals later in development; in the final game, the only humans that appear on-screen are the player characters. Copper and Booker would later reincorporate the scrapped redcoat motif in Animal Crossing: Wild World and Animal Crossing: City Folk.
Contributed by game4brains
Attachment
In the iQue release, the Carp is recolored red.
Contributed by game4brains
The game was originally developed for the Nintendo 64 Disk Drive, and would've utilized the console's internal clock to track real-world time, making the game seem truly alive. However, because of the Disk Drive's commercial failure, Dōbutsu no Morí, like many others, was moved to a standard Nintendo 64 cartridge, with the internal clock being built into the cartridge itself.
Contributed by game4brains
Dōbutsu no Mori (Animal Forest) was the starting point for the Animal Crossing series. The game was the last first-party title to be released for the Nintendo 64 in Japan.
Contributed by DidYouKnowGaming