Ways for a Magus to improve his mount?

[Red Bear]

Excluding having a GM that lets you find or buy an animal or magical beast that's already strong.

A warhorse is very squishy having low AC and low hit-points.
Is there a way to get an animal companion-like progression to your mount?

(I'm at level 5) or maybe I should just wait for phantom steed.

[Geddy2112]

There is, but it requires three feats.
1. Nature soul-+2 to knowledge nature and survival, +4 at 10 or more ranks
2. Animal ally. Requires nature soul and character level 4. Gets druid animal companion using your class level -3 as druid level.
3. Boon companion- Treat your effective druid level as 4 levels higher for the purposes of animal companion/familiar.

So you can get this at level 5, but would require retraining three feats.

[Ninjaxenomorph]

Mounted magus isn't the best choice; the only use phantom steed is for you is for overland travel. Since, if you're in combat when you get it, you can just cast Fly for a much better bonus. If you just want a mundane mount, and a heavy warhorse just isn't cutting it, you might be able to look at what friendly races have better mounts. Drow riding geckos are fun.

[exelsisxax]

Buy boots of haste and get off the horse before combat. "carry you around the rest of the day" is all a magus needs or wants in a mount.

[Kurald Galain]

Buy boots of haste and get off the horse before combat. "carry you around the rest of the day" is all a magus needs or wants in a mount.

...not quite.

While mounted, you can wield a lance as a one-handed reach weapon.

The easiest way to have a scaling mount is to ride your familiar. Failing that, a good defense is to cast Vanish (or Invisibility) on it every combat, assuming it won't be the one making attacks. Casting Bear's Endurance on it also helps.

[Red Bear]

There is, but it requires three feats.
1. Nature soul-+2 to knowledge nature and survival, +4 at 10 or more ranks
2. Animal ally. Requires nature soul and character level 4. Gets druid animal companion using your class level -3 as druid level.
3. Boon companion- Treat your effective druid level as 4 levels higher for the purposes of animal companion/familiar.

So you can get this at level 5, but would require retraining three feats.

Very interesting


...not quite.

While mounted, you can wield a lance as a one-handed reach weapon.

The easiest way to have a scaling mount is to ride your familiar. Failing that, a good defense is to cast Vanish (or Invisibility) on it every combat, assuming it won't be the one making attacks. Casting Bear's Endurance on it also helps.

What familiars are large?

[Firebug]

Very interesting
What familiars are large?
Not exactly large, but you can choose the Mauler familiar Archetype to make any familiar medium sized, and then take the Undersized Mount feat on the character.