President Donald Trump unleashed a fiery tweet about Special Counsel Robert Mueller on Friday and Twitter responded in kind, poking fun at the president's spelling mistakes and outlandish claim that the Mueller probe is "illegal."

The president reiterated his conspiracy theory about former FBI Director James Comey being a leaker, something which Trump believes led to the "Special Council" was "established based on an illegal act." Note the misuse of "council," rather than 'counsel.'

"James Comey illegally leaked classified documents to the press in order to generate a Special Council? Therefore, the Special Council was established based on an illegal act? Really, does everybody know what that means?"

The spelling mistake, which the president has made more than once, did not go unnoticed.

"You just can't seem to spell counsel correctly. Is that a Wharton thing?"

The digs continued.

"Actually it's a Trump U thing."

Contrary to Trump's bizarre assertions, Mueller was appointed by the Department of Justice after the president admitted to MSNBC's Lester Holt that he fired Comey over "the Russia thing," which he continues to describe as a "witch hunt."

Twitter immediately pounced on Trump, with users offering up theories that might explain the president's ire.

"It might mean you are the only guy over 70 up after 11pm..." one person wrote in response to Trump, who asked, perhaps rhetorically, what having an "illegal" investigation means.

Others had alternate explanations.

"You know your lawyer sucks, because the first thing any lawyer tells you is to shut the hell up."

Critics of the president simply didn't hold back.

"I don't think you know what anything means, really."

On Friday evening, Trump issued another angry tweet, this time about former Democratic National Committee Chair Debbie Wasserman Schultz, whom Trump mistakenly called "Wendy." The naming error was corrected, but not before Twitter had the chance to fire back.

"Just heard the Campaign was sued by the Obstructionist Democrats. This can be good news in that we will now counter for the DNC Server that they refused to give to the FBI, the Debbie Wasserman Schultz Servers and Documents held by the Pakistani mystery man and Clinton Emails."

@realDonaldTrump/Twitter

"He's just making people up now," tweeted Bill Palmer.

"Wendy Wasserman Shultz is the perpetrator of the Bowling Green Massacre," wrote another Twitter user, recalling a terrorist attack that White House Adviser Kellyanne Conway once referenced. It never happened. "Jeez."