They are urging people, for example, to use phrases like "bringing home the bagels" instead of 'bringing home the bacon'.
The tweet led to outrage online, with Hannah Else believes that changing idioms is not the solution.
The tweet, which has been shared nearly 10,000 times in 24 hours, includes the caption, "Words matter, and as our understanding of social justice evolves, our language evolves along with it".
On Tuesday, PETA tweeted advice on how people can remove "speciesism" from daily conversations.
Instead of: "Kill two birds with one stone". Instead of the expression "beat a dead horse", it offers the somewhat comical alternative "feed a fed horse".More news: Rockstar Games announce updates for in-game economy balancing
For instance, rather than saying, "bring home the bacon", PETA suggested saying, "bring home the bagels".
PETA's tweet recommended using substitute language when referencing animals.
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.
Social media users have mocked the alternate phrases, with one person saying, "Come on PETA, there are bigger fish to fry". "All we can say is this: Human supremacists need to start thinking about other species' interests in not being exploited". A few others criticised PETA for not taking into account the feelings of plants, who had replaced bulls in the revised list.