Meaning
What does This Kills the Crab mean?
This kills the crab also known as sad crab or optimistic crab refers to a popular image macro series, depicting a soft-shell crab, that’s facing decapitation by scissors.
The image macro is often paired with humorous captions, many of which are centered around the acceptance of death by the crab, while others are commenting on the obvious; the crustacean is facing imminent annihilation.
via MEME
Origin
What's the origin of This Kills the Crab?
The original image comes from an issue of the Fine Cooking magazine, published in March 2010.
One of the recipes in the copy showed readers the method of fixing a meal using a soft-shell crab, paired with an illustration of how to send the animal into the afterlife, along with the image captions “This kills the crab”.
Spread & Usage
How did This Kills the Crab spread?
The illustration and the captions were soon reposted on Tumblr’s Certified Bullshit Technician blog as well as Woosk.
“This kills the crab” would emerge as a meme on Reddit and FunnyJunk in November, 2010.
The meme’s popularity reached its peak in April, 2011, when it started appearing in the /ck/ board of 4chan.
“This kills the crab” would emerge often throughout the 2010’s, on parodies, image macro memes as well as GIFs on sites like 4chan, Reddit, Tumblr and Imgur.

External resources
- Know Your Meme – This Kills The Crab