I submitted this magic item to the Paizo RPG Superstar competition, but sadly it didn’t make the cut into the top 32 (which are all very cool – if you want 32 more new magic items that have been voted as good by a bunch of game designers, go get ’em!).
Mine was designed to fill a gap – for classes that want to focus on “pets,” there’s not a lot of magic items that enhance that (besides a “wand of magic fang” or whatnot). Thus, the Harness of the Hero’s Helper. Short form is if you hold their leash/reins/whatnot then you’re treated as a level higher on the Animal Companion Base Statistics table (or similar familiar table, for familiars). The beauty of this is it can work for paladin/cavalier horses, or druid/ranger animal companions, or sorcerer/wizard/witch familiars.
Harness of the Hero’s Helper
Aura moderate transmutation; CL 9
Slot neck; Price 35,000 gp; Weight 2 lbs.
Description
This leather animal harness resizes to fit any kind of beast in a form appropriate for its type. When the owner keeps the harness lead in at least one hand, which requires them to be mounted on or in an adjacent square to the animal, the animal’s base statistics increase as if the owner were one level higher for purposes of serving as a bonded companion or familiar (including a druid’s or ranger’s animal companion and a paladin’s or cavalier’s mount). Bonuses granted are treated as morale bonuses, and extra hit points disappear when the effect ends and are not lost first like temporary hit points. The effect ends immediately if the owner releases the lead.
Construction
Requirements Craft Wondrous Item, animal growth; Cost 17,500 gp
What do you think?
Geek Related 
Looks to me to be a decent idea but far, far too weak for the cost, to be honest. I can’t see a player paying 3,500 gp for +1 level of companion benefits, let alone 35,000. Maybe if it was +4 effective levels, and you didn’t have to hold it, then it might be worth something, but what good is this for casters who want to use their familiar to scout?
Hm, I priced it as low as I thought I could get away with. You can’t price for “a scouting familiar,” you have to price for “druid with killbot” or “cavalier who has a big ass tiger.” And for good or ill, in Pathfinder/3.xe, wondrous items cost. 3500 isn’t as much as a normal stat bump item, and on a good level a AC level bump gets +1 BAB, another HD, a feat, and a natural armor bonus… I would like to see the cost lower too but certainly not that low… And if it’s like 5k then every high level character will always have one. I could see $10k maybe.