>dess is the knight

Pointing out physical features doesn't mean much
>Antlers like Dess/Carol
>Body like papyrus
>Sword like a bat (Dess)
>Hand holes like Gaster
>Body matter like the shadowguys
The knight feels purposely designed to have conflicting design elements, plus we are working with the assumption that the undead vibe is because dess is dead, which we don't know, it's entirely possible that the knight is a third party that we have never seen or really heard of before. People always like to theorize but become so certain of them that we forget Toby Fox loves to subvert expectations