According to the ADL, the cartoon, also known as the "sad frog meme," proliferated in online forums such as 4chan, 8chan and Reddit along with other memes promoting "anti-Jewish, bigoted and offensive ideas" before reaching viral status on more mainstream online platforms such as Twitter and Facebook.
Pepe memes joined the Swastika, blood drop cross and "(((echo)))" symbol as anti-Semitic hate symbols, according to the Anti-Defamation League.
"Once again, racists and haters have taken a popular Internet meme and twisted it for their own purposes of spreading bigotry and harassing users," ADL CEO Jonathan A. Greenblatt said. "These anti-Semites have no shame. 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 Pepe character was originally created by artist Matt Furie for a comic titled Boy's Club about a group of anthropomorphic animal roommates, which also included a dog, a bear and a wolf.
Furie told The Atlantic separate images of Pepe appearing incredibly happy and sad were eventually singled out and became popular in messages boards without any kind of hateful context.
"It's never bothered me, in fact it's been kind of inspiring to me," Furie said of Pepe's initial online popularity. "Just seeing how mostly kids and teenagers, and kind of the youthfulness of Pepe, is what I'm attracted to, and it's been an inspiration and something that I'm proud of."
Furie said he believed the negative interpretations would eventually go away.
"I think it's just a reflection of the world at large," he said. "The Internet is basically encompassing some kind of mass consciousness, and Pepe, with his face, he's got these large, expressive eyes with puffy eyelids and big rounded lips, I just think that people reinvent him in all these different ways, it's kind of a blank slate. It's just out of my control, what people are doing with it, and my thoughts on it, are more of amusement."