I think i'm gonna get nuked later, anyway.
First thing is, both Papyrus and the Knight have a really similar shape to not say the same shape or body type, beside of this they both share the ability to fly/float, (We see that when Papy leaves after we finish his puzzles). Something that kinda pisses me off is, Papyrus IS NOT innocent, as we see in lots of dialogues, he contradicts himself a lot, and says lies when others are around him, when we're at Snowdin (Idr where) and call Paps, he says ice cream and snow aren't different, but then at Hotland he contradicts hismself by separating both ice cream and snow, in his date with Frisk, he mentions the Sun, but at the pacifist ending he doesn't know what's the Sun, and coveniently, all the others are around him, not just Frisk. Besides, Paps might be even smarter than what we think, he made a electrifying invisible maze by himself, he painted the bridge towards Snowdin to make it more dramatic, bro made his sink taller, he made a cardboard sentry thing, he basically is a god when drawing and is very smart by what he has shown, (Proof)
Also, Papyrus has said like 6 puns in the entire game, and as far as i know, that's more than the puns his brother has told, which contradicts himself because he claims to hate puns, or at least he does when Sans is nearby. Here proof cause you surely don't believe me.
Also, Pap never ever gets his mittens/gloves off, which could be like in frozen, it's a synonym of hiding one's true self, this reforces the fact he pretends to be silly, when he's a master mind of deceit, lmao he lies more than shadow milk cookie, and that dang cookie is deceit itself. Or he just doesn't because Sans tells him to do so, i mean, i'd honestly freak out if i saw someone with holes on the palm of their hands.
Other thing, the sock in their room might represent Sans' depression, and the fact Papyrus wants HIM to pick it up, Pap could just pick it up himself but that wouldn't help Sans to be better.
Something that shows that Papyrus HAS to be the Knight.
This attacks of the Knight are WAY TOO similar to Sans', and seeing how Sans is Pap's older brother, why wouldn't he teach his lil bro to defend himself? Even more when we see how Sans treats Papyrus, he mostly treats him like a kid and/or someone defenseless.
Hey papy, why'd you say something like that?
He's really tough, that's surely why Flowey wraps him with 4 roots. Doubt this helps but uhhh i need to show it, they're really similar.
Another thing where Pap and the Knight are way to similar, is their jaw, look at this
pleu
similar aren't they?
Some people says this is a bird, BUT WHEN DOES IT FLAP IT'S "WINGS"??? Eh, it just flies like a scarf in air more than a bird flying..
"But Papyrus doesn't have antleers??" shush i know, good counterpoint, but only lasts long enough until you know that's a dang helmet
"why would he wear a helmet with dang antleers" erm, idk, might be the same reason those guards also wear helmets with horns, and work for Asgore.
Knowing how desperate Paps is for validation and having friends, he would put on the helmet to match the holidays cause he might be working with them. Or else the determination extractor thing Gaster planned and Alphys created, which is similar to gifttrot or a deer skull. Though, the antleers the knight has isn't similar to any the holiday's.
Also watch out this
Papyrus has the symbol thing the PK Starstorm dude has, with the same placement too.
This thing the Knight does might be like telekiesis, something both Sans and Paps have.
Also, the fact only Sans moves his arm when using the telekinesis to control the gravity on Frisk's is just bc depending on how much a monster moves, the more they want to kill you.
more similar attacks
Also, just like Papyrus, the Knight doesn't kill you in this part of dr. And if im not wrong, Pap also is able to control his attacks and leave Frisk at 1 hp.
The knight made the tv world didn't it? Pap loves the color red and cars, he even owns one at the pacifist ending, which makes it clear, he has to be the Knight HE'S THE KNIGHT-
Man also made this, and Pap likes this puzzles, Sans literally thanks Frisk for giving Paps the reason.
This fog appears when we finish defeating the Knight and is similar to the fog during Pap's fight.
There is people who says this is a representation of how Dess is the Knight but uhh.. What is that thing exactly? The Knight doesn't have two eyes, and certainly his only eye isn't even cyan.
* At the end of Chapter 5, whatever the Knight does to Asgore