Wasp Assault Walker
The Wasp Assault Walker is a modified version of the Eldar War Walker used primarily by Eldar corsairs. They are slightly tougher and more maneuverable than your basic chicken walker, although that is not saying much since they are just as likely to collapse on themselves if they face a Lascannon or Khaine forbid, a Meltagun. Unlike the standard War Walker, the Wasp is equipped with a jet-assisted antigrav system that allows it to be deployed directly from a Vampire Raider, similar to the Grav-Chute Sentinels used by the Imperial Guard. When it gets on the ground, it can then use its jump jets to leap across the field at will.
Wasps operate in squadrons of one to three walkers and for armament are fitted with two heavy weapons, either Shuriken Cannons, Scatter Lasers, Eldar Missile Launchers, Starcannons or Bright Lances. In addition to their jump jets some Wasps will also incorporate Spirit Stones...for some reason yet unknown.
Wasps are kind of a situational unit to be honest. They are faster and more agile than the already fast War Walker, but they are still outclassed in the shooty department by the likes of a Wave Serpent neither are they as tough as a Wraithlord nor as fast as Vypers. They along with the War Walker are considered as "meh" and are often replaced with more effective walkers. They are only used in times where the need for fast scouting attacks that can provide some Dakka is providable or used as cannon fodder due to their relative cheapness.
In 8th Edition, Wasp Assault Walkers are marginally more useful due to being among the few vehicles that don't suffer from the damage tables that many larger like transports and tanks deal with. One useful niche they fill is that they can act as relatively cheap heavy weapon platforms that can have up to three models in a single Fast Attack slot, freeing up your Heavy Support slots for Dark Reapers, Wraithlords, or more goddamn chicken walkers if you can't get enough of the derpy things. A plus that the wasps have over their cheaper ground-bound walker kin is that they can deep-strike anywhere on the field (with all the usual caveats of course) and since they can fly, can ignore terrain and enemy units and get out of dodge extra fast. Comes in handy when the opponent tries to tie up your Wasps in melee; simply fly away and fire a few shots into their squad as you bounce off to safer horizons.