Donkey Kong (SSBU)/Down special
DK's iconic grounded down special is commonly referred to as gHS (grounded Hand Slap). This move is DK's longest ranged attack and also hits a good deal behind him. However, gHS can only hit an opponent that is on the ground. The move normally has two hits, but can be extended by pressing B while he slaps the ground. Typically, it is not recommended to extend the move unless the next loop is sure to hit the target. Based on it's unique properties, it is a core part of DK's neutral with several main uses.
Simply put, gHS is an unreactable answer (frame 12 attack) to all grounded defensive options. It counters crossup rolls, usually hits retreating rolls, and beats spot dodges most of the time. When gHS is fresh, they can't jump or roll out of shield between the first and second slap. If they panic and just hold shield, a third slap will break their shield. It's long reach also allows it to be used as a safe on block attack from around 2 DK's away.
Due to hitting such a large area so quickly, gHS can be used in many situations. Using gHS allows DK to safely cover multiple options in tech chase and ledge trapping scenarios. It can be used to safely and quickly destroy explosives, traps, or pretty much anything created by an opponent. Taller characters can be hit below DK even while the latter is on a platform depending on how high the platform is. This can start combos if the last possible hitbox connects. Even if it doesn't start a combo, putting anyone above DK is very good.
Since the ground control of gHS is so dominant, the main counterplay is to jump and approach from the air. Despite being countered by jump-ins, Donkey Kong can counter by running back and catching a landing with gHS. This is especially effective to condition an opponent to jump, allowing DK to use his amazing back aerial or up aerial. Using gHS against characters with low air speed and range like Luigi or characters that stay grounded like Little Mac is game changing. An important quirk of gHS is that it will trigger every counter except Joker's and Incineroar's even if they do it in the air. For some reason, gHS will also destroy Diddy Kong's Peanuts midair (not really useful, but pretty cool). Against Luma specifically, gHS whiffs unless Luma is detethered via Rosalina's neutral special or after getting knocked away.
DK's gHS can be edge canceled (also referred to as slap slip) by holding forward with sufficient momentum near an edge. Doing so allows him to slip off much closer to the ledge/platform than running off normally. With very good timing, a B-reverse gHS enables DK to slip off backwards.
The entire swing of the second hit is a spike, unlike most other spikes with arcs. This makes aHS a reliable spiking option from various heights and angles. That combined with it's low cooldown also makes it his least committal spike offstage. aHS can also be b-reversed or wavebounced to cover different recovery options. Usually the first hit combos into the second, but it does fail to link sometimes.
Due to it's low 10 frame landing lag, it can combo into pretty much anything at the right percents. Hit 1's weight based knockback means it will combo into jab, tilts, and grab at all percents if done as low to the ground as possible. Hit 2 has a 20% chance to trip if they are grounded (only possible if hit 1 missed). If both hits of aHS connect at mid percents, beware that aHS can be teched. The landing lag can be cut short if edge canceled by holding forward when you have enough momentum to slide off.
B-reversed aHS is a key mixup in DK's arsenal. Since DK's air speed is relatively high, the sudden shift of B-reversed aHS can confuse the opponent and let DK land unscathed while in disadvantage. It can also be used to attack unexpectedly while retreating if wavebounced or B-reversed. The attack itself can be as safe as -3 on block. As such, it's also DK's safest air move on block.
Due to the hitboxes being transcendent, they can't clang with other hitboxes. This means aHS will lose against most projectiles, but will beat/trade with Luma. In addition, the first hit's 90° angle can cause hit 2 to miss if Donkey Kong is moving backwards.
Interruptibility and animation length are as such : 7 for the startup + (loops, one is mandatory, others can be added) + ending (14 for interruptibility and 36 for animation length).