
...whereas an elf
is an IMMORTAL, tall warrior.
The Big Bang Theory Season 1, Episode 6

Because he's neither tall nor IMMORTAL,
and none of us could be the Flash.
The Big Bang Theory Season 1, Episode 6

In the words of Khan Noonien Singh
in the IMMORTAL Wrath of Khan:
The Big Bang Theory Season 3, Episode 5

And my IMMORTAL soul
gets cast down
Westworld Season 2, Episode 2