well, YES!
ok seriously, i've been playing Shyvana for quite a bit now and i've been wondering about different playstile she could use, so i made this guide.
I tried to cover as many arguments as possible but i'm still a beginner at making guide so, please, tell anything that could help me improve.
Thanks.

WHY:
Well one day i thought, it could be so good to slow that damned Sona from afar, and after thinking about that i realized that it was actually possibe: Rylai's Crystal Scepter !
So i begun to make this build.....
HAVE FUN!

This is a TROLL guide do not play in rankeds or PvP, it's just for fun and to show that ap Shyvana is actually playable.

PROs
-her E and ulti will deal tons of dmg
-her passive on E will make you do quite some magic dmg along with items: Wit's End 's passive will bring their MR down


CONs
-Lack of dmg early to mid game
-If not in dragon form she is useless
-Her E is the only source of dmg (and is really hard to hit) now not anymore because it passes through enemies

Well, summoner's spells and runes are the same as the "normal" ad jungler: http://www.mobafire.com/league-of-legends/build/tehasians-guide-to-jungle-shyvana-192406

RUNES
as marks
armor seals
mr per level gliphs
flat ad quint

SUMMONER'S SPELLS
just take Exhaust and Smite
if you don't like Exhaust you can take Flash because of the slow from Rylai's Crystal Scepter can give you the cc that you need.

Not really much to say about the masteries
normal tank in the def tree and take cdr and ap in the First tree

Sadly you'll need to always have 40 CDR because if so you'll be able to almost always keep Flame Breath on.

Not much to say, normal jungle start.


Boots for more speed to move through jungle camps, kage's because you'll want to upgrade it to Twin Shadows.
Now Spirit Stone, well you don't need the mana regen at all but the passive can help you to clear jungle camps faster and the upgrade, Spirit of the Spectral Wraith is quite a decent item, giving you all that you need apart from the mana regen obviously.
STILL VIABLE
Tiamat : its AoE is quite good for both clearing camps and stacking Wit's End
but i haven't tried it yet, more info later

Hey guys, i learnt about the last patch, the august one, and it has got both bad and excellent sides for shyvana.
now her Flame Breath passes through enemies, but it no longer stacks with AA-AP, so meh!
This build was based only on that =( , oh well if u want to one-shot someone with ur ulti this build is still viable, and it still has got some fun!

12/08/'13: added Tiamat at the items section