Person? - Yes.
Mortal? - No.
...from the Third Age? - No.
Halfelven? - No.
Is it an Ent? - No.
(And yes, in the second, wider sense a Dwarf would be mortal, too, if you're a pedant with words and their meanings like I am - hence my occasional difficulties in answering questions like that with a simple 'yes' or 'no'.


)