King K. Rool (SSBU)/Side special
King K. Rool throws his crown forwards, before it returns like a boomerang, akin to his appearance in Donkey Kong Country. This move is central to King K. Rool's advantage state, being able to control many options at once, as well as having combo utility off of the returning hit. Crownerang has a number of advanced techniques allowing the pickup animation to provide movement options as well, giving King K. Rool significant momentum if the player makes good use of them.
As King K. Rool throws Crownerang, he gains damage-based armor of 12% on frames 6-63. This is effectively 14.4% in 1v1, as it is unaffected by it. Due to the FAF being 64, K. Rool is able to shield immediately to completely stuff out multihits thereafter, which is useful against moves such as Sonic's forward aerial. The armor also helps heavily against juggle-centric moves such as Corrin's up aerial when staled. This is immensely helpful for his disadvantage, armoring through even Nikita. This makes it a good ledge option as well; releasing from the ledge and jumping up and forward with Crownerang can stuff out many ledgetrap setups.
Once K. Rool throws Crownerang, it is treated as an entity that spawns hitboxes, rather than a simple projectile. As a result, it is impossible for a projectile to "beat" it out; it can only have the hits negated. This makes Crownerang an excellent way for King K. Rool to defend against projectiles. It is also difficult to contest with aerials capable of clanking (such as another King K. Rool's forward aerial), as it moves deceptively quickly when going forward.
Crownerang has a small hitbox increase on frame 65 (or frame 39 post-toss) to serve as a double-hit, though this is inconsistent in regards to whether it actually works. Thereafter, it returns with a speed multiplier of 0.3×, only that it will send opponents towards King K. Rool. It can also assist with disadvantage, with unaware players often getting hit by the crown. When an opponent is hit by the returning Crown hit, combos possibilities are essentially subject only to the player's imagination.
King K. Rool players often use Crownerang for setups, hitting opponents into the Crown for the purpose of starting combos. A common confirm is using neutral attack's first and/or second hits to stun opponents long enough for Crown to come back, and then using the Crown to confirm up aerial as a consistent KO option. This can be done at around 95%, and the neutral attacks can be substituted with any option that gives K. Rool enough time to get the finishing hit. Forward aerial, forward tilt and up tilt are all equally useful ways to set up a combo. Holding opponents in place using neutral attack can also greatly assist with this, though precision and reaction time are needed to ensure that an attack doesn't cancel the returning Crown's knockback.
Crownerang is also used as a stage control tool. Using Blunderbuss's Kannonballs is also a common way to set up a horizontal wall that characters like Ganondorf have difficulty getting past. This can be used with forward aerial for a quicker way to set up the wall as well. Punishing the opponent's attempt to avoid the projectile allows for relatively decent zoning. This is slow however, and often requires significant distance to properly set up, often leading to players using one of the two before approaching instead.
Despite its benefits, Crownerang is extremely slow, with the Crown only being tossed out on frame 27, with an FAF of 63. While the armor is very helpful, the slow nature significantly weakens its potential, as well as its use as a neutral tool. K. Rool players often find themselves losing significant momentum when throwing Crownerang, with little reward against a player who can avoid the returning hit unless the player sets up for it. It also loses heavily to throw invincibility, forcing K. Rool to undergo a Crown cancel due to entering the "grabbed" animation or hitstun. The slow nature also makes it much worse at zoning as it would initially seem, with opponents such as Roy being able to cover large amounts of distance in a second and punish the throw. The sound cue from K. Rool's grunt also makes it extremely reactable. In addition, while it has a number of advanced techniques, they fall apart due to the amount of setup and level of reaction time required to make use of them.
Crown Catch & Crown Pickup Technical Data
King K. Rool has a constant searchbox for Crownerang once it becomes an item. It is clear to players when it becomes an item, as an arrow above it shows who it belongs to. In this state, if K. Rool collects the Crown, he will suffer lag with an animation, with an FAF of 28. This is often called Crown Pickup. If K. Rool picks it up as a projectile, however, it only has an FAF of 18, which is known as Crown Catch.
Picking up the Crown is treated as a special move however, allowing K. Rool to wavebounce or b-reverse the animation (Often kept under an umbrella known as Crown Bouncing, as these animations can be done multiple times in a single instance). It also changes his air speed, enabling momentum transfers into his double jump. This also allows K. Rool to slide across the ground with it, which is known as Crown Sliding, which has combo (namely a grab confirm at 0-10%) and movement utility.
Both animations are capable of autocancelling (sometimes called Crown Landing or NIL Crown), and due to the momentum being lowered, can execute NIL. This is often used alongside Crown Bouncing with a double jump (sometimes called Crown Jump due to various differences between it and a normal Crown Bounce) for platform movement. A double jump Crown Bounce onto a platform can very often autocancel the animation with zero landing lag, giving K. Rool some game state momentum in tight situations.
Crownerang's hitboxes are also programmed to always send in the direction it is going.
Returning Crown will keep its hitbox until it hits the ground and the item arrow appears. Thus, the final hitbox change is to signify when this comes up: it can technically remain active infinitely.