Stormboyz
The Orks answer to Assault Marines, Stormboyz are atypical greenskins with even less instinct for self preservation, strapped into a highly unstable and barely functioning missile that we like to pretend is a Jump pack.
In Fluff
Stormboyz are straight up odd. The Stormboyz have their own sort of culture that's quite unlike most other greenskins. They respect authority, keep their uniforms clean... hell, they have uniforms. Stormboys don't just practice fighting by getting into a scrap like other orks, they actually train, and in battle this training seems to work. Stormboys are known for cunning plans and suspiciously well orchestrated strikes.
In Crunch
The stormboyz are fast, faster than normal jump infantry. Not only can they cross impassible terrain with their packs, but they can choose to run for an extra 2d6" (risking some wounds if they do). If they don't take their normal move, they can get one reroll on their charge dice and add Hammer of Wrath to the attack. Finally, in a Waaagh! they can move 12" + 4d6 inches (with a single die reroll) to assault potentially up to 36", a feat that can't be matched by any other infantry in the game. contraction space wolf wulfen can now do that every turn so ya...
In statblock, Stormboyz are absolutely the same as typical boys at a slightly higher cost (+3 points). Given the benefits these silly rokkit packs offer, that's pretty much a steal, though depending on your situation a squad of shootas might do you better. Like standard boyz mobs the Stormboyz can bring a single Nob along for a bosspole and powerklaw, and also like the boyz they can be taken is squads up to thirty. Nothing quite like thirty hooligans hopping 36 goddamn inches across the board to but some sharp bits into some heads.
Note'able Gits
Boss Zagstruk is a unique warboss with his own Rokkit pack, leading a specialized group of Stormboyz known as Da Vulcha Squad.