Immortality

No Pal spawns with Immortality. That rules out the usual advice — you can’t start a breeding chain from a Pal that already has it, because there isn’t one. Here is where it actually comes from.

• Mutated eggs

  Every mutated egg hatches with 2-4 rainbow passives already on it. That makes mutation the most common way these show up — though you don’t get to choose which ones. What mutated eggs hatch into.

• Catching wild Pals

  Rainbow passives do turn up on wild catches — several players report finding them on low-level Pals in the starting zone, so it’s worth checking what you catch rather than assuming breeding is the only path.

• The surgery table

  Once any Pal of yours has it, the surgery table can move it, and it can then be inherited normally through breeding.