Ridley pauses and winds up before performing a sudden tail stab. It has a long startup and hits some distance away. It does minimal damage and knockback if he hits with the base of his tail, but if the sweet spot at the center of Ridley's tail tip connects, the target will be impaled while being dealt almost 10 times as much damage; both the sour spot and the sweet spot deal very little shield damage, however. The sweet spot hit causes the opponent to crumple, similarly to a fully charged Focus Attack. Despite requiring very specific precision, it is capable of piercing two opponents at once, though the extra damage from Ridley yanking out his tail will only apply to the "main" target. While the sweet spot deals extreme damage, the opponent gets to act 4 frames before Ridley, making followup attacks based on reading the opponent's getup option. During the sweet spotted Skewer animation, Ridley is invulnerable and cannot be made to flinch or take damage. Skewer is one of the few special moves in the game that will cause a Special Zoom.
When landed in the air, Skewer will simply send the victim at a roughly 30 degree arch after the tail yank, and has low set knockback. During the animation, neither Ridley or the stabbed victim are effected by gravity, though will descend after Ridley yanks his tail out, meaning the crumple animation can still occur if both are low enough to the ground. Ridley is actually able to act before the opponent in this circumstance, but the launch distance and Ridley's fall speed prevents any true follow ups.
A sweetspotted Skewer will ignore any armor from the opponent, including Joker's Rebel's Guard, Wario's Wario Waft, and Ganondorf's Warlock Punch, due to being a "hitgrab" type of move similar to Buster Wolf. While certain damage reduction attributes such as King K. Rool's Belly Super Armor will still apply, the crumple state and animation will play out as usual, though in King K. Rool's case specifically, the "Belly Armor Break" animation will play out instead. Because of this, only true intangibility can safely contact the sweet spot of Skewer without harm.
Due to the sheer damage output the move deals in a single hit, it's possible to OHKO Ridley if the sweet spot activates certain counters, such as Tetrakarn, Vision or Counter Surge. However, due to Skewer being a disjointed move that can be used while falling, it's possible for Ridley to just barely be out of range for certain counters, like Palutena's. The highest percentage Ridley can handle is around 50% from King K. Rool's Gut Check.
The attack can't do damage behind a wall, and the sweet spot does not work in Home-Run Contest.
In version 8.0.0, characters in grab invulnerability take the full damage of the sweetspot, but do not undergo the hitstun or Special Zoom. In turn however, the move was buffed in raw damage even more, eclipsing Roy and Chrom's Neutral B moves in damage and becoming the most damaging attack out of all playable characters. The damage buff has also allowed Ridley to still break King K. Rool's Belly Armor in one hit despite the latter's HP buff to their ability.
While Ridley is unable to cause the crumple animations on various boss characters and Assist Trophies, they still endure the full damage of Skewer, and can even instantly knock out some Assist Trophies.
Ridley has never been seen using this exact move in the Metroid games, but many of his attacks in the series involve jabbing with the large spike on the end of his tail, making this attack another of the many ways Ridley uses his tail to his advantage. Outside of the games, Ridley used a very similar tail stab in the canonical 2002 Metroid manga to fatally wound Gray Voice, a Chozo who was one of Samus Aran's adoptive father figures and the one whose DNA was used to augment Samus's own. The move can also be referenced to Metroid: Other M during the attack of Adolescent Ridley in Sector 1 where he tried to stab Samus. He has a delay in his attack allowing her to shoot the tail with a Missile. Proteus Ridley also preforms a similar move during his boss fight in Metroid:Samus Returns, functioning nearly identically as a tail stab with long start up that does dangerous damage at the tail spike, though Ridley primarily uses it while airborne and aims it toward the ground here.