Title text:
‘Ugh, I’m never going to be like spiders. My descendants will all just be normal arthropods who mind their own busines and don’t do anything weird.’ --The ancestor of a bunch of eusocial insects
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3199/
Everything evolves into a crab.