https://wccftech.com/nier-replicant-ver-1-22474487139-new-papa-nier-mod/

A new NieR Replicant ver.1.22474487139... mod that has been released online this week introduces a fully playable Papa Nier for the game's main campaign.

The Papa Nier mod doesn't introduce a simple model override, as it uses the correct animations and voice clips seen in the World of Recycled Vessel where players do control the character. Unfortunately, the mod doesn't yet change the model in cutscenes.