Just weeks after "The Daily Show" host Jon Stewart took Cramer to task for trying to turn finance reporting into a "game," famous bear economist Nouriel Roubini criticized Cramer on Tuesday for predicting bull markets.

"Cramer is a buffoon," said Roubini, a New York University economics professor often called Dr. Doom. "He was one of those who called six times in a row for this bear market rally to be a bull market rally and he got it wrong. And after all this mess and Jon Stewart he should just shut up because he has no shame."

Cramer recently wrote in a blog that Roubini is "intoxicated" with his own "prescience and vision" and said Roubini should realize that things are better since the stock market bottom in March.

Roubini said in 2006 that the worst recession in four decades was on its way. He has attracted attention for his gloomy — and accurate — predictions of the U.S. financial market meltdown.

Roubini said the latest surge is just another bear market rally following the pattern of other rallies after the government intervened. He expects the market will test the previous low because of worse than expected macroeconomic news, disappointing earnings and because banks will fail after the stress tests come out.

"Once people get the reality check than it's going to get ugly again," Roubini said.

Roubini said Cramer should keep quiet.

"He's not a credible analyst. Every time it was a bear market rally he said it was the beginning of a bull and he got it wrong," Roubini said in an interview with The Associated Press.

Roubini could be wrong too, of course. Predicting the future is treacherous. But he's been right more often than not, which is something Cramer most certainly cannot say.