Old Zogwort is a special character equivalent of a Weirdboy, more expensive obviously, slightly stronger and also with access to a cool special trick. So what's he got different from a standard Weirdboy? Aside from a name...
Weirdboy "Zogwort" Gazzar - my Deff Skullz count-as character.
First off, Zogwort is a bit tougher than your standard Weirdboy, having a Toughness of 5. That makes him that bit harder to wound with shooting and in combat, and having the bonus of needing a S10 weapon in order to insta-kill him. Very handy indeed!
He's got an extra wound over your standard Weirdboy too, alongside the same amount of Attacks, topped off with an extra D6 attacks - striking at the same time as Marines - to represent his snakes.
Even better is the fact that ALL of Zogwort's attacks are 2+ poisoned weapons, meaning wounding Monstrous Creatures and tough targets is easy for Zogwort with his possible 9 attacks. He could if you're lucky, solo a Carnifex in a single round of combat.
Zogwort has access to all of the standard Weirdboy powers, and has the bonus of being a Warphead as standard. The next special thing he offers however, is his unique Psychic ability, "Zogwort's Curse". This is one of the most fun Psychic powers in a game - although can be quite limited in it's use.
Instead of rolling on the standard Weirdboy psychic power chart, Zogwort can instead attempt to turn an enemy character into a Squig and the best thing is, they get no saves whatsoever, just a straight tougness test. Awesome!
Zogwort is a decent buy, especially if you like Psykers, Weirdboy Powers and face some Independent characters regularly. He's also handy in the fact he has a Poisoned Weapon, along with a high, albeit random, possible number of attacks.
Warboss "Wazdakka" Nobrot MK2
Wazdakka is a cross between a Big Mek and a Warboss, sitting somewhere in between in terms of stats. He's a real handful for enemies to deal with, especially when tucked in a unit of Nob Bikers or Warbikers.
Boasting a base toughness of 5, with an increased 6 from the Bike, he can be a tough customer in close combat - cutting through people with his Power Klaw, as you would expect from a bike mounted Warboss. He also automatically comes with your bog standard upgrade for a Warboss - the Bosspole, ensuring his Bike mob doesn't run away as much.
Something people don't realise (and I also don't have a clue why he has it) is that Wazdakka has a Kustom Mega Blasta, meaning he can have a pop at Terminator characters and whatnot.
His bike is where Wazdakka shines however, being able to Turbo Boost AND shoot in the same turn. Not only that, but when you look at the gun it can shoot - the Dakkacannon - it's excellent. 4 S8 shots, even with Ork ballistic skill, can easily ruin light vehicles, allowing Waz and his Warbikers to steam roll over anything that spills out.
The final thing Wazdakka brings to the table for you though, is the ability to make Warbikers a Troop Choice. Some people prefer Nob Bikers (me personally) but Warbikers do play a good part in a Speed Freek army, the ability for them to be troops with constant 4+ cover saves, or 3+ cover with Wazdakka turbo-boosting and shooting his Dakka cannon is a fearsome prospect.
I used to use Wazdakka a lot, but now settled for my Warboss on bike purely for the points cost.
Mad Dok Grotsnik
Mad Dok Loony "Grotsnik" - Chief Painboy of the Deff Skullz
Mad Dok Grotsnik is mental. He's a hybrid Warboss and Painboy, but he really excels in a few situations. He comes with your standard Painboy items - so whatever unit he is in gets Feel No Pain and he has the choice of attacking with a Poisoned Weapon, although 9 times out of 10, I'd prefer to use his Power Klaw.
Grotsnik however suffers from a bloodlust style special rule, where he and his unit become fearless, but must move as fast as possible towards the nearest enemy unit and assault if possible. Which, if you're staring down the face of a Trygon, C'Tan or something similar is a troublesome prospect.
What Grotsnik does bring to the table is Cybork body upgrades for ANY model, and for Independent characters, they get a 5pt discount. Not amazing, but it's still 5pts saved somewhere.
Grotsnik and Meganobz are where it's at for me personally. The reason I don't like to use Meganobz is their lack of being able to purchase Cybork Bodies and a Painboy. Solution around that is to attach Grotsnik to the unit.
It does mean however that they're a big points sink, but Fearless Meganobz with 2+/5++ and Feel No Pain are a force to be reckoned with. Even more so if you can spare the extra Warboss to make them scoring, then attach him to a Boyz mob.
Warboss "Ghazgkull" Nobrot
Now... the biggest of the Green meanies, Thraka himself. What he brings to the table is pure and simple PAIN. He's big, he's tough and he's more than capable of taking pretty much anything on in combat.
Thraka gives you your usual Warboss benefits - a close combat monster, Power Klaw, very tough and ability to take Nobz as Troops. You then chuck onto this his Mega Armour and special rules and he's going to be prime target for your enemy.
First off, he's got 5 attacks basic. You add onto that, on the charge he gets +2 attacks for his Adamantium Skull - which also makes him immune to Instant Death. No stray Vindicator shot or S5 Power Fist Weilder is going to be smashing Thraka into pieces. He's more than capable of dishing out the punishment to his foes... and that's without his bodyguard being near.
His special rule "Prophet of the Waagh!" means the standard Ork army Waaagh! is replaced by Thraka's version, and it's a whooooole lot better!
First off, for Thraka, in the turn he Waaagh's, his saving throw is invulnerable... meaning he's even tougher to kill off. Use this time wisely to target big stuff, tough characters or things like Necron Pariahs. The Waaagh also lasts during your opponents phase too, meaning you've got 2 assault turns worth of 2++ saving throw!
Then you add in the fact he makes any Waagh-ing Orks on the table count as rolling 6's AND fearless, he makes the army work around him.
On the downside, he is EXTREMELY expensive. More so than the unit of 5 Meganobz you want him leading, or 2 other Warbosses combined. But, if you fancy a turn of absolutely destroying your opponent - provided you time it right - then Thraka is the Ork for you.
I rarely use him outside of Apoc games because I like to run him and Grotsnik in a unit of 5 Meganobz, scoring, with Feel No Pain, 5++ saves and in a Battlewagon. So yeah, extremely points heavy.
Ork special characters are the embodiment of the force - they're very fluffy, can be very random but also some of the most fun characters you will face in 40k.
Thraka may not be as reliable as Abaddon, but I know who I'm cheering on!