Though Nintendo’s not going after Pocketpair because lamballs look uncomfortably similar to wooloos, we do know the company is famously litigious in protecting its brand.

So no one really knows what exactly Nintendo is accusing them of yet.

Here’s an older video by an attorney that did a deep dive on Palworld and its legality: https://www.youtube.com/watch?v=ns3ATH556NU (Warning: long video).

Edit - Update:

A patent lawyer Was able to narrow down which patent that they could allege was infringed by looking at the combined patents between Nintendo and The Pokémon Company (since they filed a joint lawsuit). There are 28 possibilites and they are claiming that multiple patents have been infringed. https://gamerant.com/nintendo-pokemon-palworld-pocketpair-lawsuit-which-patent/

One likely candidate is a patent that was filed (and requested that the review process be expedited) in July of 2024 that’s “primarily centered on creature-catching mechanics”.