Out of all the Marvel superheroes out there, a whopping TWO of them can truthfully say they've never killed someone. Who may these heroes of restraint be? None other than Spider-Man and the Wasp.
Now you may be thinking that there must be other heroes who make the cut, but as Comic Book points out, if a hero, such as Iron Man or Captain America, directly helps with killing someone, that's enough to count against them.
Thanks to the creation of a chart which contains a list of Marvel films, we can clearly see who was killed, who killed, who assisted in the kill and how the kill was executed.
Spider-Man does come up on the assist list, but technically he only presented the idea of killing Ebony Maw, he didn't actually do it.
Similarly getting off on a technicality is the Wasp, because it's never clearly shown or stated that those who lost to her in battle actually died.
Reigning in the highest number of kills is Thanos who, according to the chart, has made a total of 19 kills.
Thanos is responsible for the deaths of, at least: Heimdall, Loki, Gamora, Vision, Winter Soldier, Scarlet Witch, Falcon, Groot II, Black Panther, Spider-Man, Star-Lord, Drax, Mantis, Doctor Strange, Hank Pym, Nick Fury, Maria Hill, Janet Van Dyne and Hope Van Dyne.
Considering he made a majority of these kills with just the snap of his finger in Avengers: Infinity War, it's unsurprising that he takes the title.