>>33131522Only Pokémon in the Human-Like Egg Group or Ditto.
Theoretically you could breed with a Pokémon that's in both the Human-Like group and another group, and then your offspring could breed with could breed with anything in that egg group, allowing the possibility of endless human/Pokémon hybridization.
But as we've seen hybrids don't seem to exist in Pokémon, or if they do we'd have to use actual breeding methods and not just the "dude eggs lmao" mechanics in the games.