Alternate Paladin mounts RAW?

[Winter_Born]

So I'm rolling a Paladin for a home campaign, as well as a mirror of him for PFS play.

What are the allowed mounts for a medium sized character for both RAW Pathfinder, as well as for PFS play? I like the stereotypical warhorse, but I'm wondering what all the options are.

Cheers!

[Ciaran Barnes]

The entry for divine bond suggests you select an animal from the druids' animal companion list that is appropriate as a mount.

[Ryu Kaijitsu]

a paladin Archetype can allow you to have lions or similar exotic animals as mount, I can imagine a lion riding paladin easy enough, both the rider and companion being armored in mithral