So... Fizz.

All his abilities scale with AP. Sure... got it. So let's do this.

Let's build him AD.

***UPDATE!!!***

Since his recent nerf to his ratios and mana costs, Fizz is now MORE OBVIOUSLY THAN EVER best as an AD off-tank champion. Choose this build over ANY AP build out there. It's been updated for a more up-to-date build better suited for the current meta.

Now I may get some flack for this, but I honestly believe AD Fizz trumps AP Fizz. AD Fizz has a jump that adds some damage to his normal attack as well as activating procs. Sound familiar?Yeah, her. Fizz IMO plays like a buffed up Irelia with more utility. His Q is very much like her Q. His W adds damage to his auto attacks (Uh... Hiten Style anyone?). His E is a bit of CC but also great for evening up a fight 1 on 1 or perhaps focusing down one person in a team fight. His ult is a skill shot though honestly very different from Irelia's (much better IMO).

So with all that in mind... let's Jungle... and play Fizz AD. LET'S GO!

Pros:

His W makes jungling CAKEwork.
Great initiate with Q.
His E is broken for its ability to dodge spells and let him survive BAD situations (a la Nidalee and her Pounce).
His ult is some great single target CC and a hilarious disruption in team fights.
He has ridiculous and unexpected burst damage.
If you build him beefy enough, his W can do some REALLY GREAT lasting damage in team fights.
Grievous Wound. It's OP.
HE SUMMONS A FREAKIN SHARK!

Cons:

All his ratios ARE through AP, though they are actually pretty bad ratios post-nerf.
His abilities require that you be right in the middle of a team fight, though with Playful/Trickster that's not so bad.
He's focused in team fights, but again, Playful makes that okay.
He takes a bit of finesse figuring out just how long you can stay in a fight.
He's not Stitch. I wish he was Stitch... :'(

He's a jungler who does some great burst damage. 'Nuff said. Smite + Flash.

AS Marks x9
AS Quints x3
Armor Seals x9
MR/level Glyphs x9

Runes have been updated for the new build. Since Fizz relies on two different types of damage at two different times (Magic damage early to jungle with trident and Physic damage later to deal damage with his Q, Atma's, and Trinity proc), I do not run penetration marks OR quints. Instead I run full Attack Speed Marks and Quints as well as MR glyphs for late game tankiness.

I've gone to 9-21-0 masteries now. The defensive tree is STILL the best for tanky junglers, but I think Fizz really needs that 10% armor pen late game since I don't run any runes for penetration.

Nimble Fighter:
His passive is one of his two abilities that makes him a really great jungler. It reduces the damage taken from basic attacks and... ALL jungle creeps attack through basic attacks. It starts at 4 level 1 and with the defensive masteries as well as your armor seals, he will literally ignore the damage from some of the smaller creeps (little wolves, little wraiths, red buff small guys). It's great and it's BROKEN for jungling

Urchin Strike:
HIS Blade Surge. Let's see everything that it does.

It jumps to a target if it is at max range. Closes for ganks from river.
It damages by his AD as well as a bonus (100 flat at level 5).
It activates procs including Sheen/Trinity Force and Red Buff.
It can pull you far behind a target if you get caught too close.
He looks like a torpedo... CMON NOW!!!

This ability is amazing for ganking. Coupled with his W, you will deal (huehue Phreak) TONS of damage. AD Fizz should level this first after two early levels in his W because this Q deals the most damage with its on hit proc.

Seastone Trident:
The heart and soul of Fizz. It does DoT damage to whatever you attack (broken). It activates a Grievous Wound if you activate it (broken). It does MORE damage the lower it's health is (broken). It does BONUS damage if you have it active (broken). With this ability + early Smite (OMG DID HE SAY SMITE EARLY?!?!?) you can take blue by 2:10. Level this first for jungling at 1 and 3, but don't max it until your Urchin Strike is finished.

Playful/Trickster:
The new Sanguine Pool. This ability is so troll it's not even sensible that they made it like this. It can negate tower shots. It can negate Caitlyn's ult. It can negate KARTHUS'S ULT. It jumps over small walls, AND it slows on impact. TOO much utility in one ability. This is what really makes him broken. Being able to dip and dive around those REALLY painful abilities is just too good.

Chum the Waters:
HERE FISHY FISHY FISHY FISHY! This ability is so freakin cool, I love it to death. Initiate from the river with a fish to slow any single target. THEN a gigantic fish comes out knocking them up and doing some decent nuke early (not so great late if you're going AD). I think it's most important facet is that it's a HUGE shark in the middle of a team fight. It can cause some mass disruption in late fights... IF you can land a skill shot XD.

Like most junglers, start off with Cloth Armor and 5 Health Pots. Once through the camps and hopefully after a successful gank, back to spawn and buy...

your typical Razor + Boots jungle items. With these, you will be prime to re-clear the jungle and continue ganking/counter-jungling your opponent. Try and roam around/jungle/farm until you have ~1450 gold for...

your Wrigs and Mercs. Like your typical Off-Tank jungler, Fizz THRIVES off these two items. You may also consider CDR boots of Tabi (ONLY if they are STUPIDLY AD heavy), but Merc's are generally the best to go with on Fizz. From here, you'll need to make a decision. If you are getting a good number of Kills or Assists from ganking or are farming EXCEPTIONALLY well, go straight for Sheen. However, now is a good time to get...

if your ganks or jungle are not building you enough gold. If you are getting ganks done well or farming jungle well, then head straight for...

Phage. It's a GREAT early game item for ganks. If you happen to land the slow proc (ESPECIALLY ON YOUR INITIAL Q) during a gank, wrap it up and seal it with a bow on top, free kill for Christmas.

Here is the main arsenal of your kit. Wit's end provides 55 MR for a short while off only 2k gold worth of a GREAT item. It provides for great damage as well as anti-mage tankiness for mid game. Next, build right into warmogs. With the damage from your abilities and Wit's End, you won't need much more in your kit, so we can start building tanky. Once Warmog's is done, it's time to be a typical tanky DPS jungler and get...

Atma's Impaler and finish off that Phage into either Trinity Force (for extra damage from Q proc) or Frozen Mallet (less suggested, but good if you need more tankiness and crowd control). Finally, sell off that now useless Wriggles for a Guardian Angel.

Start out with your Cloth Armor and Potions and head to Blue Buff camp. Get Seastone Trident first and have someone leash blue for you. Make sure you have someone with CV watching their jungler, because in order to optimize your W, you should Smite it AS SOON as the leash hits. Your W does more damage the lower their health, so Smiting early leads to a faster buff. This does leave you susceptible to a counter jungler, so be sure of where their jungler is. If you cannot (no CV or misses with it) then save smite for the last hit.

After finishing blue camp, get your Q then take wolves and wraiths quickly. Spam your W + Q onto big wolf and blue wraith (W active puts a wound that decreases Blue Wraith's healing). After you get level 3, get a 2nd point in your W, then head right for Red Buff. If you have been using potions properly until here, you should have 2/3 more left and still be at 2/3 health. If you know where their jungler is and feel safe, Smite early again to kill it quickly. If not, last hit with smite as usual. Finally hit the small golems and prep for a gank after taking your first point in E at level 4.

With Red Buff and your Q, a gank should be no problem. Activate W and initiate with Q for a slow. Then auto attack them and do your best to dodge stuns/CC with Playful / Trickster. P/T is also great for re-closing if they blink or Flash to create distance. If they STILL somehow get away, a flash + more red buff slow should be enough to secure any kill.

Fizz is a great all-around champion and in my opinion actually needs some nerfing. He has SO MUCH utility that in both ganks and team fights he SHINES. AD Fizz beats AP Fizz as far as contributing to a team, but feel free to play either. In any case, I love the little guy, and I am sure you will too. ENJOY!!!