I've been looking into getting an unusual/non standard mount for a character of mine...

And I know that there are vermin mounts out there. But how does that work? The rules that I see is that to be able to be trained it has to have an intelligence... yet vermin don't have intelligence. So if I were to get one how would I train it? Is there some magical device that is needed/used? And how many tricks can a vermin learn?

The creatures I was thinking about as possibilities:
-Dire Weasel (large)
-Giant Wasp
-Giant Dragonfly
-Giant Spider
-Hippogriff
-Krenshar (large)

I would be interested in other ideas as well.

I'd just say to create your own like creating a monster.

Pick your creature or make a list and assign a value then roll to see what you get.

(1)Dire Weasel (large)
(2)-Giant Wasp
(3)-Giant Dragonfly
(4)-Giant Spider
(5)-Hippogriff
(6)-Krenshar (large)
In this case roll a d6 and see what you get.

Intell is basicly in 10 groups:
INTELLIGENCE is the equivalent of human "IQ." Certain monsters are instinctively cunning; these are noted in the monster descriptions. Ratings correspond roughly to the following Intelligence ability scores:
(0)0 Nonintelligent or not ratable
(1) 1 Animal intelligence
(2) 2-4 Semi-intelligent
(3) 5-7 Low intelligence
(4) 8-10 Average (human) intelligence
(5) 11-12 Very intelligent
(6)13-14 Highly intelligent
(7)15-16 Exceptionally intelligent
8 17-18 Genius
(9)19-20 Supra-genius

21+ Godlike intelligence

So roll a d20 to determine the range. If you roll a 20 then roll a d10 to see the plus. But in your case do you want a mount that in smarter than you?

As to how many thing you can train it to do. Well list all the thing you want give them value ranges as you see fit guided by the intelligence it has and roll to see if training worked. Those it didn't learn can be taught later and reroll to see if it learned.

You can build a sheet like a monster sheet to give to your DM to show how you determined things and see if he will accept it.

So basically, build a monster.
There may be some rules already on determining what your horse can do, see if you can use that and us it as guide.

All the existing rules that I can find are all based on intelligence. An animal has an intelligence of 1-2 and can learn 3 'tricks' per point of intelligence.

But vermin don't have an intelligence score. And I know there are rules out there for having vermin mounts...

But because the training rules are based on intelligence, and vermin doesn't have the score... by that rule it can't be trained and learn any tricks. :/

What is great about this game is that you can make up your own rules. Just show how you came to your conclusions.

Use similar information and extrapolate. (For Vermin, use Rat to start with and then get creative. )(They may be from an alternate universe or a different plane of existence and somehow got stuck here when a rift opened.)

Do you want your creature to be smarter than horses?
Horses are animal 1 intelligence.

Tell how you found such a fine creature. Perhaps they originally were normal and selected by Fey creatures and bred as small mounts. Then some were transformed by a Wizards or Shaman spell of growth but kept their large size. Then they were bred as large creatures for mounts.

If you can support it most DM's will allow it.

Don't let lack to published rules stop a good fun idea.