As far as hate symbols go, this one may be the least alarming. After all, it's just a cartoon frog. 

The Anti-Defamation League (ADL) declared Tuesday the popular internet meme Pepe the Frog, a cartoon frog derived from an early 2000s comic strip character, to be a hate symbol. But it did not start out that way. Before fringe conservatives on the "alt-right" made the meme indistinguishable from its white nationalist agenda, Pepe the Frog was a playful, "feel-good" internet joke that even popular celebrities had a hand in spreading. 

The origins of Pepe the Frog date back to 2005, when comic book writer Matt Furie featured the frog as a character in the series "Boy’s Club." The comic featured the childish antics of the teenage monster characters Pepe, Brett, Andy and Landwolf before gaining popularity on the internet over the next few years.

One of Pepe's most infamous moments came in a 2008 comic strip when he pulled his pants down to his ankles to urinate. The frog's relieved facial expression was absorbed by the internet and, along with the accompanying phrase, "Feels Good Man," transformed into one of the all-time great reaction memes. The meme inspired the complimentary "Feels Bad Man" meme of Pepe crying and "Smug Frog" meme of Pepe stroking his chin. Pop stars like Katy Perry and Nicki Minaj eventually got in on the game. 

Then things changed.

In late 2015, "alt-right" internet trolls launched a purposeful campaign to reclaim Pepe the Frog as a symbol of their ideology, according to the Daily Beast. Social media users mashed up Pepe with Nazi propaganda imagery — everything from a Hitler mustache to a swastika — to link the two symbols. The movement spawned on 4Chan and eventually moved to Twitter, where many white nationalist-Donald Trump supporters embraced the cartoon frog as proxy symbol for their candidate — Trump's trademark haircut now sits atop Pepe in many users' posts. 

The craze came to a head last week when Donald Trump, Jr., the GOP nominee's son, shared a Photoshopped image of the movie poster for the action film "The Expendables" with the faces of Trump and many of his most prominent supporters pasted over the faces of the movie's stars. The image was re-titled "The Deplorables," a reference to Hillary Clinton's characterization of many of his apparently racist supporters as being in her "basket of deplorables." The new poster featured Trump standing beside none other than Pepe the Frog. 

Trump, Jr., perhaps unwittingly, cemented Pepe the Frog as one of the faces of white nationalism. For many, the image was the first they had seen of Pepe and the less favorable identity the meme had taken on and became the primary one discussed by the media. The ADL was quick to respond, declaring Pepe a hate symbol later that month. 

"Images of the frog, variously portrayed with a Hitler-like mustache, wearing a yarmulke or a Klan hood, have proliferated in recent weeks in hateful messages aimed at Jewish and other users on Twitter," the ADL wrote in a statement. "Once again, racists and haters have taken a popular Internet meme and twisted it for their own purposes of spreading bigotry and harassing users."

Not everyone on the internet is content to let the "alt-right" keep Pepe and many still post the meme with its originally intended, if vague, meaning. But as far as the ADL is concerned, the case is closed.