The Grass Mud Horse is a Chinese Internet meme and kuso parody based on a word play of the Mandarin profanity cào nǐ mā (肏你妈), which means "fuck your mother".

It has become an Internet chat forum cult phenomenon in China and has garnered worldwide press attention, with videos, cartoons and merchandise of the animal (which is said to resemble the alpaca) having appeared.

Some variants of the animal are known as "Fertile Grass Mud Horses" (沃草泥马, Wò Cǎonímǎ, which resembles 我肏你妈, Wǒ cào nǐ mā, "I fuck your mother").

A cartoon about the Grass Mud Horse attracted a quarter million views, and a nature documentary on its habits received 180,000 more hits in the same amount of time.

[20] The "Grass Mud Horse" became widely known on the English-language web following the publication of a New York Times article on the phenomenon on 11 March 2009,[8] which sparked widespread discussion on blogs.

In 2009, renowned artist Ai Weiwei published an image of himself nude with only a 'Caonima' hiding his genitals, with a caption "草泥马挡中央" (cǎonímǎ dǎng zhōngyāng; 'a Grass Mud Horse covering the center'.

It is an illustration of the "resistance discourse" of Chinese internet users with "increasingly dynamic and sometimes surprising presence of an alternative political discourse: images, frames, metaphors and narratives that have been generated from Internet memes [that] undermine the values and ideology that reproduce compliance with the Chinese Communist Party's authoritarian regime, and, as such, force an opening for free expression and civil society in China."

Caonima is an expression of a broader Chinese internet culture of spoofing, mockery, punning, and parody known as e'gao, which includes video mash-ups and other types of bricolage.

[25] The Beijing Television Cultural Center fire led to Chinese internet users creating a number of digitally manipulated image parodies, including one with a Caonima's outline in the smoke.

Industry observers believe that the move was designed to stop the spread of parodies or other comments on politically sensitive issues in the runup to the 20th anniversary of the 4 June Tiananmen Square protests.

[11] Some of these citizen efforts to keep the Grass Mud Horse alive have moved offshore to the U.S. and elsewhere, including for example the creation of an independent Canadian publishing house (see Mudgrass Press) referencing the meme.