Pathfinder questions (my players, don't look!)

Hey guys, as you know I am converting Expedition to Castle Ravenloft form D&D 3.5 to Pathfinder.

I have an NPC, well more like an encounter really, with a completely insane character. The problem is, it used a template from Heroes of Horror for that, and well, since I'm not converting Taint rule from HoH to keep thing simple, and also because I'm starting to get a bit tired of converting 3.5 stuff, I need another solution.

How would you make a complete raving lunatic NPC?

I don't know Pathfinder so apologies if this is no help, but could you roll for personality traits every couple of rounds? So the character could seem lucid, but perhaps worried about something trivial, then you roll and they are jubilant and singing, roll again and they're paranoid.

Like I say, I don't even know if these types of traits are in pathfinder, but you could make a table with 20 entries and roll whenever it seems appropriate.

That's an interesting idea, but it doesn't exactly help as the original template I was talking about made the base creature be under a constant barbarian rage... This is the sort of madman I'm looking for.

I see. Sorry I can't help then.

Is there not a barbarian class from Pathfinder? Why not just give the NPC the Barbarian Rage class feature (but make its uses unlimited and its duration: until knocked unconscious), then give the NPC a handful of rage powers (3 or 4 to keep conflict interesting).

I was definitely thinking of giving him some barbarian levels. I am currently checking a list of templates, in case I find something...

Oh, I think I found something, not quite what I was looking for, but it should do a nice job.

What do you guys think of a wild rager with the chaosborn template? Yes, I'm that evil XD.

Can anyone explains to me how does an imp changes into a rat using beast shape I when a rat is tiny and beast shape I is limited to small or medium?

The imp doesn't use beast shape the spell to change shape, changing shape is one of an imps abilities, look for change shape in universal monster rules, should be here.

Is there a class in Pathfinder similar to what the warlock was in D&D 3.5? There is a 3rd party one, but frankly it sucks and kind of goes contrary to what the conversion manual suggests of doing.

Okay, nevermind, I found a warlock archetype for the vigilant. I am not quite overjoyed with it, but so far it looks far better than that sucky 3rd part warlock.

Okay, wow, cheliceraes are VERY different in PF than they were in D&D 3.X. Much more lethal and not quite what I need. Any suggestion on what to do? I still need a spider-like monster capable of mimicry (kind of what green hags have) and spitting web...