A cartoon frog often used by supporters of Donald Trump has been declared a hate symbol by the Anti-Defamation League, because of its popularity with white supremacists from the "alt right" movement.

The character, called Pepe the Frog or the "sad frog," is often depicted as a squinty-eyed amphibian with wide, red lips pressed together in a sort of grimace.

The ADL added Pepe to its "Hate on Display" list on , citing a wide range of anti-Semitic variations of the character that depict it with a "Hitler-like moustache, wearing a yarmulke or a Klan hood."

"Once again, racists and haters have taken a popular internet meme and twisted it for their own purposes of spreading bigotry and harassing users," Jonathan A. Greenblatt, CEO of the ADL, said in a statement. "They are abusing the image of a cartoon character, one that might at first seem appealing, to harass and spread hatred on social media."

The character was originally designed in 2005 as a non-racist, humorous meme, and circulated through the Reddit, 4chan and 8chan communities. and Nicki Minaj helped bring the meme into the mainstream with some non-racist social media posts a few years ago, but since then, Pepe has been embraced as a mascot by some of Trump's vocal backers on the internet.

Trump tweeted an image of Pepe from his Twitter account last October, showing the frog with Trump's signature hairstyle, standing in front of a podium as President of the United States.

Trump's son, Donald Trump Jr., also shared an image on Instagram this month, showing Pepe as a member of the Republican nominee's campaign team. The image showed Trump and his allies, including Pepe, lined up as the cast of "The Expendables."

 

A photo posted by Donald Trump Jr. (@donaldjtrumpjr) on

The frog has appeared in many racist, pro-Trump tweets in recent months. Those who have embraced the meme were quick to leap to its defence this week, after the ADL labelled it a hate symbol.

One self-proclaimed white nationalist told the earlier this month that he and other like-minded individuals have been actively trying to link Pepe to their movement on the internet. "We basically mixed Pepe in with Nazi propaganda etc. We built that association," Twitter user @JaredTSwift told the website. @JaredTSwift's Twitter timeline shows a long history of white supremacist comments and pro-Pepe tweets.

The Anti-Defamation League acknowledges that Pepe was not created as a racist character, but it has taken on that association during the U.S. election campaign.

"In recent years, with the growth of the 'alt right' segment of the white supremacist movement鈥� the number of 'alt right' Pepe memes has grown, a tendency exacerbated by the controversial and contentious 2016 presidential election," the ADL says on its .  "The mere fact of posting a Pepe meme does not mean that someone is racist or white supremacist," the organization adds.

Pepe is only the latest alt right-inspired addition to the ADL's Hate on Display list. In June, the ADL condemned the alt-right movement's practice of writing names or phrases inside triple brackets, to "single out Jewish journalists and users on social media for harassment."