An Idea would be to integrate Pets and Mounts.

Mini-quest at predetermined level (25 phys) to get a Chocobo chick.
Which could sit on your shoulder, or follow you around.
Each level you gain, you need to return to the initial quest giving NPC to pay a Gil and/or item fee to 'raise' your Chocobo.
Once your Chocobo is of sufficient level (Player lvl 30 phys), it can switch from a pet that sits on your shoulder/walks behind/flys around with you to a summon-able mount for use outside of cities.