Pros

Necromancers and pets are awesome
Your Ghouls are named after the Four Horsemen!
Can do a lot of damage late game while staying tanky
All of his ghouls can be doing a lot of things at the same time
Late game he can become a machine with more than 3 minions up at once
Your ulimate is as good at Shaco's clone, as well as a mini Zilean ult on top!
You can make others do your work for you


Cons

A DPS build can pub stomp, which provides a false sense of power
THE GLITCHES! OH GOD!
Can be a grinding early game
Has mana problems early game
Can be very squishy
Ghouls deal magic damage, yet scale with AD
Is hard to find the line between doing damage and dying or being tanky and ignored
His ghouls can last a very small amount of time and stand around before they attack
His pets can have a mind of their own, wasting precious time for damage

These are the spells I like to take, but you can take whatever you feel makes you play better.
Ghost-Your champion ignores unit collision and moves 27% faster for 14 seconds.
I pick this spell for the same reasons. Your chasing ability is poor so by using it you can run faster, through minions and aid your team in a fight, chase down enemy champions, defend turrets or even avoid dying.
Exhaust-Exhausts target enemy champion, reducing movement speel by 40%, attack damage dealt by 70% and ability and item damage dealt b 35% for 3 seconds.
Pick this only if you love 1v1 or you go for offensive play style. Use it to save youself by casting in on the most dangerous enemy or you can save your allies by using it in a team fight on a hard melee carry or AP caster.

Unholy Covenant (Passive)
Yorick's basic attacks deal 5% more damage for each summon that is active. Meanwhile, Yorick's Ghouls have 30% of Yorick's Attacks Damange and Health.
Omen of War (Q): The last Hitter, Speed Buff/Suataoned Damage
Yorick's next attack will deal 30/60/90/120/150 (+?) physical damage and summons a Spectral Ghoul for up to 5 seconds. The Spectral Ghoul deals 8/16/24/32/40 (+?AD%) additional damage per hit and moves 15%/20%/25%/30%/35% faster. While the ghoul is active, Yorick moves 15%/20%/25%/30%/35% faster as well.

Cost: 40/40/40/40/40 mana.
Cooldown: 8.5/7.8/6.6/5.7/5.6


This Ghoul is summoned on an on hit effect, similar to that or Nasus' Q. This is the 'glass cannon' Ghoul that runs faster and hit's harder. When use right, it guarantees that last hit gold. It is your sustained DPS spell which gains extra damage every level on top of your passive. For a constant cost of 40, who can complain?
Target: The enemy hit with the spell then closest enemy/call to help.
Omen of Pestilence(W): The Nuke and Slow
Yorick summins a Decaying Ghoul that arrives with a violent explosion dealing 60/95/130/165/200(+?AD%) magic damage and slowing nearby enemies by 20%/25%/30%35%/40% for 1.5 seconds. While the decaying ghoul remains alive, nearby enemies continue to be slowed by 10%/12.5%/15%/17.5%/20% for up to 5 seconds. Cost: 50/55/60/65/70

Cost: 50/55/60/65/70 mana.
Cooldown: 11.44/11.44/11.44/11.44/11.44


This Ghoul creates a blast when it spawns, it is similar to that or Tibbers. This means it can be used over walls and such. On it's explosive entryit damages an Are of effect and slows for a percentage. After this,it attacks with your passives damage and slows the enemmy for a lower percentage while it is nearby.
Target: Closest enemy/call to help.
Omen of Famine(E): The Lifestealer

Yorick deals 55/85/115/145/175 (+?AD%) magic damage and heals for up to 50% of the damage dealt. A Ravenous Ghoul is summoned behind his target, which heals Yorick for the damage it deals and lasts for up to 5 seconds.

Cost: 60/65/70/75/80 mana.
Cooldown: 9.44/8.5/7.4/6.39/5.44


This Ghoul is your 'lifesteal' Ghoul. It is used by targetting an enemy, the spell then steals a certain amount of health and summons your Ghoul. During it's lifetime it will attack with your passives damage and heal you for a percentage of it's damage. This can be many meters away so it is essentially remote lifesteal!
Target: The enemy targeted with the spell then closest enemy/call to help.
Omen of Death(R):The Morde/Zilean Ultimate combo
Yorick conjures a revenant is the image of a target allied champion. Revenants deal 50%/75%/100% of the target ally's Attack Damage. If his ally dies while the revenant is alive, the revenant sacrifices itself to reanimate them.

Revenants and reanimated allies lose 10% of theur maximum Health per second.

Cost: ?/?/? mana.
Cooldown: 110.62/96.79/81.53


This is what makes Yorick brilliant. On cast, it will create a Revenant (ghost) in the image of the ally you cast it on. (This can be you, or another ally) It then gains a percentage of the targets damage and can be controlled by you! Similar to Mordes ult eh?

But here's the beauty of it, if the target dies during it's lifetime, the target takes control of the revenant and heals itself. This could add that little extra damage needed to kill your low HP enemy. This can be used in any fight as a defensive or an offensive spell.
Target: The enemy you attack/Tell it to attack using ALT + Right Click

With my masteries, I like to go 9/21/0 because I may get 9 from Offence, but they are purely utility and Mag Pen mastery choices.

But Yorick is an AD champion! WHy get Mag Pen?

Well, yourdeal magic damage with their effects. And with the new change to the way lifesteal works, you heal the amount of actual damage dealt rather than what you could have dealt. Therefore if your enemy stacks AP, you heal less and do less damage! And seeing as I get no Magic Penetration items this is the perfect place to get that extra lifesteal from.

I like the defence masteries because if you've played Yorick, you know that he is a horrible glass cannon DPS and fails horribly. This however adds to your early game sustainability.

Tip and Tricks

Late game best tip: Faceroll = Win
Farm, Farm, Farm. Without a farm, Yorick becomes useless
Try not to use your Omens too much too soon, you will run out of mana fast


Omen of War:

USE THIS TO FARM.
Great for last hitting
Can be used to farm minions well
Creates decent sustained DPS
Good chaser buff


Omen of Pestilence:

Can be used to block skill shots
Brilliant slow to be use in synergy with other ghouls
Can be used over walls for unexpected kills



Omen of Famine:

Vital for a sustainable laning phase
Heals you for more than you think udring team fights



Omen of Death:

Can be controlled like Mordes ult, use it to take turret aggro to get that kill
Can be controlled using ALT + Right click