He doesn't want a horse... so what does he want?
Just a 'not a horse'? Is this a flavor thing? Or does he want something that is more useful than a horse?
If it is flavor, then go freakin' wild. Put whatever scales or feathers he wants. Even if you don't reflavor, then maybe give him an axe beak for chocobo action (I don't view axe beaks as too mcuh of a problem).
If he wants something mechanical..that is more troubling. Particularly if he wants to start with this stuff. Most of the options I know of start at level 4 or 7.
He doesn't want a horse... so what does he want?
Just a 'not a horse'? Is this a flavor thing? Or does he want something that is more useful than a horse?
If it is flavor, then go freakin' wild. Put whatever scales or feathers he wants. Even if you don't reflavor, then maybe give him an axe beak for chocobo action (I don't view axe beaks as too mcuh of a problem).
If he wants something mechanical..that is more troubling. Particularly if he wants to start with this stuff. Most of the options I know of start at level 4 or 7.
Yeah, I'd say what he wants is the big question. Non-core and 3pp have some decent alternatives to the horse if he wants something that's not a horse, but still fills more-or-less the same role and is at the same power level.
If he's looking for more of a mechanical jump in power like something that can fly and/or pounce, tell him to suck it up and play the beast rider, or go for one of the feats that expands your mount options.
A camel?
The Monstrous Mount feat is basically designed for what you're talking about. Your mount or similar can be a griffon or other similar choice with that feat (and possibly the successor, Monstrous Mount Mastery.)
Monstrous Companion is a similar feat, more customizable but weaker unless you do some serious min-maxing.
Those are Paizo-created. I'm less familiar with what's been done in 3rd party outside a couple of publishers which I don't think have touched the cavalier.
Tell him to play a Ghost Rider cavalier. He gets a Phantasmal Horse he can summon at will. screw trotting into a dungeon on a normal horse.
I second this. The cool points you get for having a phantasmal mount you can summon at will outweighs any of the drawbacks of that archetype.
Ghost rider's from Occult Adventures.
The exact options available via monstrous mount are griffon, hippocampus, hippogriff and worg.
He's not so crazy he's running after a griffon or a construct horse, just something that he could start with that's different then a 'another horse'. The axe beak sounds promising and the 'every class suggests this' camel is too close to a horse.
As for what he 'wants' it's up in the air. He's willing to wait for the creature to 'grow up' to large size so he can ride it eventually, and he's okay with just about any theme. I'm not taking them underwater, but underground and through cities and forests. He's- of course- interested in anything that can fly, is somewhat more partial to dinosaur-like creatures, and likes anything that's weird or has a fun ability, even if it's less powerful as a fighting mount. He's torn between being a mounted-archer and a lancer. Hopefully that gives a bit more direction.
Side note: Ghost rider cavalier sounds neat as brix. What's it from?
If he wants a dinosaur mount, there is the Beast Rider Fear to open up a few dino options.
Another idea.
I was just commenting on a guy's thread who was thinking about a Halfling Eldritch Guardian with a Mauler Familiar and riding it. He was thinking Flying Fox.
Stealing for the fighter guide.
1. A red deer (a large elk)
2. At a slightly higher level, an Alce Griffon (it's wingless).
Go to d20pfsrd.com
If anything, just give him an animal companion from the ranger list at his cavalier level, it follows the same template and everything.
If you're looking for alternatives to the mount itself, there are very few. The Daring Champion has potential, but it comes with a lot of baggage like using a Dueling type style. The Castellan gets bonuses for tactical positioning and high ground. There's another one that gets a bonded gun, but you're probably not into that.
Alternatively, the samurai class which is the alternate to the cavalier has some great options, like the Yojimbo which gets armor training.
You could play a Half-Orc for the Beast Rider feat enabling elephants, pteranadons, rhinoceroses, stegosauruses, or triceratops.
Edit: Ninja'd by Chengar Qordath
Tell him to play a Ghost Rider cavalier. He gets a Phantasmal Horse he can summon at will. screw trotting into a dungeon on a normal horse.
It could be reflavored as a phantasmal camel :P . Actually as long as he keeps to the mechanical concept, it can be reflavored as god knows what.
Speaking of which, if you as DM are okay with it, you can reflavor the horse itself as pretty much anything as long as you keep the horse stats - it won´t make any mechanical difference. If you decide that it´s a chocobo with a "kiss the bird" apron with the same stats (apparently kicking rather than making hoof attacks), so be it. To be honest horses may be bland conceptually, but are very solid mechanically - few creatures start large and thus rideable from level 1.
Spider mounts are awesome, but I'm a big Drow fan.