When a guy curls up into a ball and then proceeds to pull a Durex X-tra Strentgh Condom over his entire body.
He will stay within the condom for the next week, while occasionally discharging bodily fluids. The mixture of shit and cum are evenly distributed all throughout the condom, enclosing the man in a chrysalis of sorts. After the 7 day period, the guy then bursts out of the condom and flies away with his newly developed butterfly wings.
Ah, the beauty of nature.

Metamorphosis, also infamously known as 177013 as it's page number on the site nHentai, is a Japanese hentai comic created by mangaka Shindo L. The hentai gained popularity online and a cult following for it's grim, realistic, and depressing storyline.

// SPOILERS BELOW //

..Do you want my advice? Don't read it. Unless you're willing to see a woman go through the five stages of grief during pregnancy and inevitably dying by the end of the comic, yeah you can read it.

Something Big and Black Man Ray yells at each other in skype calls FOEVER