Fizz are being played both as AP and AS/AP Those who play him AP Focus on all his spells damage well, while this build focus on the auto attacks with Fizz' Seastone Trident and the damage over time items Wit's End and Malady.

PROS:

Very Agile and Mobile - Can escape almost any gank and even dodge spells and ultimates using Playful / Trickster
Decent Farmer
Excellent Harasser and Tower Diver again thanks to Playful / Trickster
Easy to land and use Ultimate
High Damage
Strong Game throughout *early to end game*


CONS:

Playful / Trickster are Fizz' greatest way to engage when you do engage u need to land ur Playful / Trickster perfectly, if you don't hit it you can use the Urchin Strike
High Difficulty but greatly rewarding to master
Squishy

The Runes are focused in the build.
Marks: Magic pen, this increases the damage you do with all your spells, and are only buffed with the boots in the build
Seals: Seals focus on the attack speed which is needed to damage even more and poke faster on your enemies
Glyphs: Flat CDR helps you to more often poke your enemy with the Seastone Trident
Quintessences: Flat ability power increase your start abilty which also is chosen to increase your damage output at the start

Pretty much the same to the champion spotlight

Max out Seastone Trident First: W

The second skill for you to max is your own decision if you prefer AOE more than single target spells Maximize your E and then Q otherwise Max your Q before your E

Obvious but put a point in R whenever possible.

I use Ghost and the new summoner spell Surge (can't be picked as summoner spell)

Ghost is great for getting near your enemy and land your Playful / Trickster

Surge only makes everything about this build better.. you will get more AP and even more attack speed.

Playful / Trickster are Fizz' Most unique skill, this with Urchin Strike are 2 great Gapclosers and good for hunting and engaging

It aint really hard to farm as Fizz his Seastone Trident makes it alot more easy to farm because of the dot Just make sure to last hit all the minions you can with good farming and some champion kills you secure your team and you a good game, if they do play aswell