Originally posted by Toasty the Ghosty:

I have debug mode on and i can't figure it out, I remember hearing that if the corpse rots it isn't immortal but i'm not sure about that. Any way to find out?

The corpse will have Immortal in it's health tab

The corpse rots slower and it wounds heal, jut put everything in the freezer and if the corpse looks healthier than it should it's probably an immortal.

you can also check the dead pawns wounds, they slowly heal over time, If you think you have one note the damage on all wounds and check back later, if one changes from yellow to green that is a yes for immortal. also if you put them in a freezer strip them if they are not colonists because they will try to break out after they revive

Originally posted by Toasty the Ghosty:

I have debug mode on and i can't figure it out, I remember hearing that if the corpse rots it isn't immortal but i'm not sure about that. Any way to find out?

While on debug mode, click a pawn, go to health then put a green tick on Hediff so you can see in the organs menu at the right hidden statuses.

If the pawn is immortal you will see immortal(FirstDeath)