Crawler from Worm

Crawler one of the Slaughterhouse Nine from the Web serial "Worm" [link] . Seriously go read this its really awesome .

lets see from the cast page

Crawler – Male. Brute. An inhuman monster.

In Crawler's case the phrase "What doesn't kill you makes you stronger" is literally true. Every time he is hurt his body adapts, rendering him more resistant to whatever hurt him or giving him other capabilities or features. He regenerates very quickly and the advantages gleaned from any such regeneration are permanent, making him look less and less human.

Crawler intentionally submits himself to suicidal situations so he can become even stronger. He has been doing it for sometime now.