How much do you wanna bet that he gets incinerated by Daenerys's dragons when she takes Westeros?
Let's review the facts.
- Gregor is a zombie, or at least that is the assumption though some users here think he is 100% alive, but he doesn't talk, his skin looks pale and decayed, he is impervious to regular weapons and he is more of a mindless bodyguard - though not so mindless that he can't understand insults - than the vicious bloodthirsty barbarian we knew (though we know he is still powerful and can still kill violently).
- If wights are any indication, zombies can only be killed by fire.
- Gregor is currently Cersei's bodyguard, and Cersei is now queen of Westeros, so she's the one Daenerys has to defeat to get the Iron Throne, and she's finally sailing the Narrow Sea. And of course she has all three dragons with her.
When it inevitably happens, will people finally stop saying Gregor is alive, since he - zombie or no - will be nothing but ash once the dragons are through with him?