Instead of saying "kill two birds with one stone", the organization wrote, why not "feed two birds with one scone?".
The tweet led to outrage online, with Hannah Else believes that changing idioms is not the solution.
"Words matter, and as our understanding of social justice evolves, our language evolves along with it", PETA said.
The animal rights group then provided followers with alternative variations of common phrases "to remove speciesism from your daily conversation".
With the tweet, PETA, a high-profile animal rights organisation, have managed to drive their agenda while sounding tongue-in-cheek at the same time.
In another tweet, PETA took the bull by the horns, er, "took the flower by the thorns" and explained its reasoning.
Not only do the PC editions of the time-tested idioms make little sense - Twitter was quick to point out how where there's a will, there's a way to find someone who will be offended by even the "correct" version.
However, many people took to Twitter to suggest more phrases, or mock the suggestion. Instead of "curiosity killed the cat", for example, one Twitter user suggested "curiosity thrilled the cat".
PETA has faced backlash for its suggestions. "To everyone else: add your own anti-speciesist phrases below!"