I'm playing a Ghost Rider Cavalier, so my mount acts as a Spiritualist's Phantom. And we've run into question regarding whether my mount needs to breath (for purposes of going underwater or Mass Suffocation).
Opinions are equally split between "It's a Phantom, just physically manifested ectoplasm, so obviously no." and "It's listed as an Outsider not Undead, so obviously yes." And I mean split equally when I asked my local PFS for a rules call and got a 50/50 of these responses.
Can I get an official ruling?