The creator of Elon Musk’s favorite cryptocurrency says he’s a ‘grifter’ that doesn’t understand coding ‘as well as he made out’

Elon Musk may love Dogecoin, but the cocreator of the meme-inspired cryptocurrency isn’t fond of the Tesla and SpaceX CEO.

“He’s a grifter. He sells a vision in hopes that he can one day deliver what he’s promising, but he doesn’t know that. He’s just really good at pretending he knows. That’s very evident with the Tesla full-self-driving promise,” Jackson Palmer said of Musk in an interview with Australian news outlet Crikey that published Monday.

Palmer, who is Australian, said he and Musk have an “interesting past,” mentioning the first time he messaged Musk on Twitter years ago.

At the time, Palmer wrote a code script that would detect and automatically report cryptocurrency scams posted on Twitter, he said, adding that he gave the script to Musk and crypto influencers. He said “it became apparent very quickly that [Musk] didn’t understand coding as well as he made out. He asked, ‘How do I run this Python [programming language] script?’”

After that, “I wasn’t a fan of him. My opinion on him and all billionaires is that I don’t care much for them.”

In 2013, Palmer and Billy Markus created Dogecoin as a joke based on the “Doge” meme, which portrays a Shiba Inu dog. Markus and Palmer didn’t intend for Dogecoin to be taken seriously, but to their surprise, the community surrounding Dogecoin grew exponentially. Nonetheless, both left the Dogecoin project in 2015.

Musk has become an adamant supporter of Dogecoin, tweeting and hyping the cryptocurrency consistently over the years. In addition to investing in Dogecoin, Musk has mentioned working with its developers on bettering its network. The billionaire even impacts Dogecoin’s price movement when he tweets or speaks.

The Tesla CEO has a friendly relationship with Markus online, but he doesn’t have the same rapport with Palmer.

“About a year ago when Musk was saying something about crypto, I said Elon Musk was and always will be a grifter but the world loves grifters. They love the idea that they may also be a billionaire one day, and that’s the dream he’s selling,” Palmer said. “When he talks to other users on Twitter, they’re like, ‘Wow, Elon is talking to me! Maybe I can be a friend of his, or even become a billionaire myself.’”

In response, Musk tweeted on Tuesday, saying, “You falsely claimed ur lame snippet of Python gets rid of bots. Ok buddy, then share it with the world.

“My kids wrote better code when they were 12 than the nonsense script Jackson sent me,” Musk added. “Like I said, if it’s so great, he should share it with the world and make everyone’s experience with Twitter better. If he does, you will see what I mean. Jackson Palmer is a tool.”

While Palmer is partly responsible for the creation of Dogecoin, he has denounced and criticized the crypto space.

“[I]t’s so easy to grift now through crypto,” he said.

Many speculate that we’re now in “crypto winter,” but Palmer disagrees. “I still see heaps of money being funneled in by crypto promoters. They’re waiting for a fresh batch of fools to come in. This happens in cycles. You wait for a while for the collective memory of the world to forget about how much of a scam it is,” he said.

“Sadly I wish it was the end of crypto, but it’s not. More holistically, in this system of griftonomics, hypercapitalism, rentier capitalism, increasingly people are doing nothing but making money off doing nothing, it’s kind of fucked us all up. It’s given people this weird mental issue that things that five to 10 years ago people would have the common sense to say ‘That’s weird,’ are okay. Now, even if it’s fraudulent, they think, ‘Do I really care?’”

This story was originally featured on Fortune.com