Since I have a bit of downtime this afternoon, I'm writing out a more in-depth idea of what I envision K. Rool's Smash appearance to be. This one is meant to fit within the parameters of SSB4, where "unique or GTFO" is a guiding philosophy, although it's not the sort of intricate submission I'd make to MYM or anything.
K. Rool:
Referred to as such in-game because of his alternate costumes that deviate from his King persona. Kaptain, Baron and Boxer are all options, and, while Little Mac has sixteen colors, eight for normal Mac and eight for Wire Frame Mac, K. Rool has four colors for each costume, totalling sixteen as well. To a lesser extent, the lack of 'King' staves off politically-correct, yet degenerate complaints that "he's another fat King who's no different than Bowser or Dedede."
General 'Feel':
K. Rool is the new heaviest character in the game, requiring roughly 10-20% more to KO than Bowser, the current heaviest. What's more, although he's not nearly as fast as he was in DKC, he's still no slouch in getting around; he moves at roughly Bowser's speed and has a reasonably high first jump. The stage audibly rumbles whenever K. Rool lands, and the controller vibrates tangibly with each step he takes as he dashes. Much like how Jr's Clown Car takes less damage than his face, K. Rool's stomach takes slightly less damage than the rest of him, due to its gold plating.
"OMG broken!" you say? Not quite, says I. K. Rool is the largest character in the game as well, being slightly wider than Bowser and slightly taller than Ganondorf (the top part of his crown clips through low platforms, thankfully not being a hitbox/hurtbox), and even then, he's hunched over slightly. That being said, many of his physical hitboxes are either close range or difficult to land, leaving his size near exclusively as a weakness. In a game where most heavyweights are designed to suck 1 vs. 1 and dominate in FFAs, K. Rool is a giant target against multiple foes while offering few to no "big powerful moves that kill everything at once" to compensate.
Although he has a handful of deceptively quick moves, K. Rool also suffers from significant lag in many instances due to his bumbling nature. To close things out, K. Rool's second jump is comparable to Little Mac's as far as gaining him almost no distance, moreso just delaying his fall, leaving him a prime target to be gimped once he's offstage (his rock-like fall speed doesn't help matters, for this or when he's being juggled onstage). Moreso than most other characters, K. Rool is the living embodiment of the phrase "the bigger they are, the harder they fall."
Specials:
K. Rool's Neutral Special is the Spiky Cannonball, which is differentiated from Jr's generic cannonball in that its primary purpose is not as a projectile. While it is a chargeable move, the cannonball's speed is low and deals minor damage in the air, its spikes not having fully emerged yet. When it lands, however, they pop out, turning the cannonball into a painful trap that lasts roughly as long as a Banana Peel (one onstage at a time).
K. Rool has a number of strategies with regard to the cannonball; it functions as somewhat of a barrier between him and attackers, making him more dangerous to approach. Cannonballs can be knocked around the stage, and many of K. Rool's moves are geared toward sending the cannonballs at specific trajectories at foes (although foes can retaliate and hit them back). This also means that the cannonball absorbs energy projectiles and stops others in their tracks, although they will knock it back at the King, who it can hurt. Custom moves allow the cannonball to roll forward along the stage or to bounce in place, both at the cost of lesser damage.
K. Rool's Side Special is the Red Cloud, a simple projectile that slows down those it hits, as if they were on the receiving end of a Timer. The cloud is slow and only affects foes for a second, roughly the length of a Warlock Punch; it's difficult to land, yet, if spaced properly, can allow K. Rool a vital hit here or there. If spammed, the cloud will occasionally crap out, speeding characters up instead. Its customizations include the freezing and reverse-control clouds. K. Rool's Down Special is the Blunderbuss Vacuum, which, in contrasting to other sucking moves, can be directed forward and backward to push as well as pull onstage elements and projectiles (pull in enemy projectiles to nullify them or shoot them back out).
Pulling in a spiky cannonball allows K. Rool to drag it around the stage or, if it reaches him, shoot it back out again to reposition it. Foes, too, can be pulled around (against their will into cannonball traps) or, if pulled into the blunderbuss, launched back out, as if they were shot out of a Smash Run barrel cannon. Its customizations include one where the blunderbuss suction decreases, but has damaging particles in its stream, and one with stronger suction that functions at a shorter range. K. Rool's Up Special is his Helicopter Pack, which basically functions as a slow variant of Fire Fox; it offers K. Rool slow, controlled flight in a single direction for a reasonable distance. It's not an awful recovery, but it's also quite easy to gimp; if the player holds 'A' while recovering, K. Rool's pack will sizzle with electricity, giving his entire body priority that can deter attackers, but that deals steady damage to him in the process. Customizations allow for a jetpack that offers a descending glide, rather than a directional boost, as well as an explosion that launches K. Rool high into the air for a great recovery at the expense of 10% self-damage.
Basic Attacks:
K. Rool's jab is his Crown Boomerang; whereas other characters can hold out their punches and kicks, K. Rool can hold out how far his crown travels. It functions as essentially an infinite-range projectile that comes at the cost of K. Rool remaining a sitting duck as he waits for it to return, gawking at the screen. His dash attack is a bull charge featuring his crown. His F-Tilt is a close-range belly thrust, his D-Tilt is a chomp that can be sweetspotted for knockback, and his U-Tilt is a DK64-esque uppercut.
K. Rool's Smash attack are unique in that they're incredibly powerful, among the most powerful in the game, yet all involve him moving around in strange trajectories that make them ineffective if just casually thrown out. K. Rool's F-Smash is a leaping belly flop that deals devastating damage to foes underneath him when he lands, but that requires careful spacing to land (and to avoid getting punished to boot). K. Rool's U-Smash involves him leaping up high into the air, spinning around to drill opponents with his crown; unless he connects with the initial hit of the crown, foes are just thrown away weakly by the move, ready to retaliate. To a lesser degree of craziness, K. Rool's D-Smash involves him collapsing onto his buttocks, releasing green shockwaves that can deal a fair amount of damage (and launch cannonballs vertically), but are only effective at a range.
K. Rool's aerials are all relatively run-of-the-mill, close range hits, far from the focus of his game, being more situational in use than anything. K. Rool's N-Air involves him spinning in a ball, throwing out his cape for a weak hit while his body itself deals good knockback at close range. His F-Air is a blunderbuss gun butt, his B-Air is an elbow smack, his U-Air is a lunging chomp and his D-Air is a blunderbuss burst of fire (that can spike weakly and slow his intense fall speed briefly). His grab is a chomp with surprising speed, but limited range. Snagged foes are in for a world of hurt, having to pay through the nose for getting in K. Rool's face and failing to effectively punish him. While his throws are generic tosses or suplexes that don't deal much damage, K. Rool's pummel is the proverbial Death Rool; the King gets down on his belly and rolls around, foe in mouth, dealing an unprecedented 6% per pummel until they mash free.
Last, but not least, K. Rool's Final Smash is The Kredits. Most thread veterans know and love this one; the King plays dead, while a series of Kredit platforms rise up from below off the screentop at high speeds, dragging hapless victims along with them. Think of this as a more chaotic version of Master Hand's new card attack. The Kredits themselves consist of the classic few from their original appearance in DKC, along with a handful of Smash-exclusive new ones.
Misc.:
Beyond being a hulking character, K. Rool's appearance onstage is distinct in that his expressions all ooze evil satisfaction at the schemes he's brewing, as well as the pain that will befall his victims as a result. He's finally back on center stage, and he'll be damned if he's not going to milk the moment and ham it up for all it's worth. Giant snaggle-toothed grins and maniacal bellows accompany every attack and animation he has, and his idle animation involves him looking at the screen and flexing a bicep. On the other hand, when he's failing, K. Rool becomes very visibly pissed. His bloodshot eye bulges (as in the cartoon) and his jaw drops, giving the distinct impression that he's both stunned and about to let out a wrathful scream; his cape also tears after he's passed 100%.
K. Rool's entrance animation involves him jetting onto the stage using his blunderbuss. He has his beloved DK64 taunt, one in which he blows smoke off his blunderbuss, and one in which he strokes his pet Klaptrap. His victory animations include maniacal laughter, leaping around in circles while spinning around, dancing (sound familiar?), and one in which he is hoisted up and down by visibly struggling Kritters. Like various other newcomers, his victory theme is separate from the Kongs', being a hard rock excerpt from his theme. His concept art involves him glaring into the screen, smiling evilly while pointing his blunderbuss directly at the fourth wall, his cape blowing in the wind behind him. Xander Mobus announces his name in a deep tone, drawing out the 'Rool' to emphasize the character's depravity.
tl;dr K. Rool's unique selling points:
--Heaviest, largest character in Smash history
--Meshes with current fighters, matching up well against close-range combo w****s struggling to penetrate his defenses, but poorly against other, faster projectile-users
--Contrasts with other heavyweights who excel in FFAs by being a heavy with a strong 1 vs. 1 leaning
--Contrasts within his own series by being a crocodilian villain, opposed to a third Kong hero, as well as by being a technology-based fighter, compared to a primitive hand and body-using fighter.
--Most unique costumes (sans Koopalings, who are technically alternate characters)
--Trap-layer capable of offensively or defensively attacking, dragging and launching his trap to his liking
--Projectile-centric heavyweight with a status effect projectile, a projectile jab, a psuedo-projectile D-Smash, and who can even turn foes into projectiles with his vacuum
--Recovery that borrows and improves upon Pichu's concept of self-damage for a higher payoff
--Mobile Smashes that are extremely high-risk, high-reward
--Grab-game that, in a reversal of the norm, uses the pummel for damage and the throws for positioning
--Wacky, unusual Final Smash that doesn't fit into any pre-existing archetypes (i.e. transformation, death beam, projectile barrage, death combo)
--New stature (obese anthropomorphic crocodile vs. a dozen normal humans)
--Distinct insane, calculating animations and expressions in-game (think Dedede's, taken Up To Eleven)
I think this about sums up what potential I think the King could bring into Smash while not overstepping any boundaries or becoming too complex to viably develop. I'm going to file this post away to promote on the website or anywhere else K. Rool's uniqueness or worth comes into question. Let me know if there's anything you'd like explained or fleshed out here.