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.