Begins with P? No.
Human? Yes?
Real human being who has taken on a symbolic significance? (*smattering of applause*) Yes, a real human being, but not a particular real human being. The "symbolic significance" part is trickier. The significance of this not-particular but real human being is indeed being defined in a symbolic way.
Mammal? See "Human?", above.

Is their identity unknown? (*some applause and a little nervous laughter*) This person is not a particular s/he because there is more than one of this person. In some cases their identity is known; in other cases not—and this observation is germane to the AOTC.

Superheroes? No. (Real human being, remember?) But heroes? Sometimes.

Head or Leader? Almost certainly not.

Medical workers? No
Secret agents? No.

Linked to particular political outlook. In principle and in general, No. But there certainly is a political link in some instances, and it's probably fair to associate those instances with (broadly speaking) a particular political outlook.
Unknown soldier? No. The fact that the identity of these individuals is sometimes known, sometimes not is perhaps an interesting feature of the AOTC, but it is not central.

Associated with particular country? No.
Tzadikim Nistarim? (

Hidden text

*googles surreptitiously*

) No.
Linked to ethnic group? No.