Though it is worthing that Nintendo is alleging patent infringement, not copyright infringement. IANAL (I Am Not A Lawyer), but that doesn't sound like they're going after the models used in Palworld, but more overall mechanics?
Possibly this patent Nintendo has for what seems to be "a thing the player throws at another thing to initiate a fight with it" (IANAL): https://patents.justia.com/patent/20240278129
Though it is worthing that Nintendo is alleging patent infringement, not copyright infringement. IANAL (I Am Not A Lawyer), but that doesn't sound like they're going after the models used in Palworld, but more overall mechanics?
Possibly this patent Nintendo has for what seems to be "a thing the player throws at another thing to initiate a fight with it" (IANAL): https://patents.justia.com/patent/20240278129