Marvel's The Defenders has recently been released on Netflix and, all things considered, it's a pretty solid show. In addition, while all of its characters that we know and love from the comic books have appeared in their own respective series, this was the first ensemble gathering of its kind on the television side of the Marvel Cinematic Universe.
However, not every character to appear in The Defenders actually originates from the Marvel comics, as some were created specifically for Netflix. This is most noticeable on the villain side of things, as four of the five leaders of The Hand (Alexandra, Madame Gao, Sowande, and Murakami) fall under this category.
Of course though, the vast majority of characters on display have long histories on Marvel's pages, some of which go back decades-upon-decades and feature numerous different interpretations. And while many of the characters in this series more or less stay true to their origins, there are also quite a few that the showrunners took some liberties with (in true comic book adaptation fashion.)
All that said, this is how some of the veteran Marvel characters who appear in The Defenders look side-by-side with their original, two-dimensional counterparts.