|Squig Hoppers on an old CD|
They're still hard-hitting and mobile, but since they're skirmishers they won't be sending many ranked up infantry units running on their own, and with attacks coming back at them (and themselves having only a moderate initiative) they will take casualties in return. Also, they are now classified as cavalry models, which makes sense and gives the hoppers a 6+ armor save and gives the model an additional S3 attack. More importantly however, it means that only the Night Gobbo on top will be allowed a support attack if you keep Squig Hoppers in your second rank. This means, of course, that Squig Hoppers won't really rise in effectiveness just because you bring larger mobs of them (like for example the Squig Herd).
They do, however, still get to charge in any direction, and enemies won't have the time for a charge reaction. This makes them quite effective at chasing down smaller missile units, who will be firing at them with a -1 modifier due to the Skirmish rule as they bounce across the battlefield, and will eat their faces once they make it there. It is also quite useful to have your Hoppers chase down Scouts and/or warmachine hunters such as Harpies, Skinks, Waywatchers, Great Eagles and Shades, who otherwise might be difficult for Greenskins to handle. Since our artillery is quite important to us, keeping a small unit of Squig Hoppers bouncing around behind your lines to chase away Fast Cavalry is a cheap investment that might end up paying off big time.
Squig Hoppers really do shine when they get to abuse their random movement, which is truly an undervalued attribute in the 8th edition ruleset. At all times, the Squig Hoppers will move 3D6, no matter if they're charging, pursuing or fleeing. This opens up a lot of possibilities. For example, if an enemy elects to flee from your hard-hitting infantry troops, it is quite possible for the Squig Hoppers to catch them in the random movement phase. Where your Wolf Riders would force an already fleeing enemy to flee a second time if they charged (also useful in some situations), no reaction is allowed against random movement, meaning the hoppers would simply hop into the enemy and destroy the unit. Similarly, if your infantry units are fighting enemies where it's likely they will beat them, the Hoppers can bounce into the enemy flank, inflict some additional wounds, but most importantly chase down the broken enemy with 3D6 against 2D6 for the pursue rolls, making it unlikely for the enemy to escape and allowing your infantry units to reform to face new enemies instead of wasting time chasing down beaten foes. In much the same way, as long as more than 25% of the unit is alive afterwards, Hoppers can act like a sniping unit by hopping into stronger foes, inflict some pain (maybe take out a soft-bellied wizard?) and bounce to safety leaving little chance for the enemy to chase you down, even if they're Swiftstriders. As long as you roll average for your 3D6, you should get away.
Finally, a fun change to the Squig Hoppers rules now allow Night Goblin Bosses (War or Big ones) mounted on Giant Cave Squigs to join up with units of Squig Hoppers. This will grant the whole unit the ability to re-roll any 3D6 for their movement, which is an excellent boost. If you to intend for your Squig Hoppers to be more of a fighting mob rather than just an army utility, this can be a great option. The Boss (with a mundane spear) and his Pet will strike as hard as 3 Squig Hoppers (plus the Stomp!) yet only take up the space of two, while ensuring that you'll make those important random movements when they count. It also increases your chances of rolling the fabled triple 6, causing each squig to inflict an impact hit on the charge. Initially I said that rule would never, ever come into effect, yet just the other day my Hoppers proved me wrong. Sadly, it was while hopping into Chaos Warhounds, whom I would have beaten anyway, but it forced me to eat my words in any case and watch how my Hoppers destroyed a unit before combat ever truly began.
Unit size: If you're looking for an excellent utility unit capable of protecting war machines or bouncing down the odd fleeing enemy, a minimum sized mob of 5 Squig Hoppers is a cheap investment that will rarely feel like a point sink and might quite often spark a key to victory. If, on the other hand, you want to make sure your Squig Hoppers will be able to fight something in almost any matchup, mobs of 7-10 Squig Hoppers led by a Big Boss on Giant Cave Squig will chew holes through the enemy flank units, and still won't cost you overmuch at all. In fact, if brought along at smaller point scales, such a unit will definitely prove valuable and a struggle for the enemy to take out. Just keep in mind that the Great Cave Squig will never get a Lookout Sir! amongst the smaller Squig Hoppers. Bringing more than 10 Squig Hoppers just isn't very cost effective. Since you rarely will be able to squeeze in more than 7-10 in combat against most enemies, you're really just buying extra hoppers for additional wounds whose main attacks can't be used for support attacks. If you really want more Squig Hoppers than 10, it's better to just bring two units of them instead.