Carl Icahn.

President-elect Donald Trump tapped a billionaire investor today as a special adviser to overhaul what the transition team calls "job-killing" rules.

Carl Icahn will be advising Trump on regulatory reform as the incoming administration promises sweeping changes to the regulatory process. The Trump team has promised to target environmental and energy rules put in place by the Obama administration.

"Icahn will be a leader in helping American entrepreneurs shed job-killing regulations that stifle economic growth," the team said in a statement.

Icahn — whose net worth is $16.5 billion, according to Forbes — has invested in oil and gas companies and other major industries. He was an early Trump supporter who has reportedly been influencing the real estate mogul's campaign and transition team on energy policies.

Trump said today that Icahn "is not only a brilliant negotiator, but also someone who is innately able to predict the future especially having to do with finances and economies. His help on the strangling regulations that our country is faced with will be invaluable."

It's unclear what Icahn's role will be and how he'll work with the White House office that oversees federal rulemaking efforts.

He will be advising Trump in his individual capacity and won't be serving as a federal employee or a special government employee, and "will not have any specific duties," according to the transition team.

Icahn took aim at the Obama administration's rules in a statement today.

"Under President Obama, America's business owners have been crippled by over $1 trillion in new regulations and over 750 billion hours dealing with paperwork," he said. "It's time to break free of excessive regulation and let our entrepreneurs do what they do best: create jobs and support communities."

Trump has promised dramatic regulatory changes under his administration.

That effort "will include a temporary moratorium on all new regulation, canceling overarching executive orders, and a thorough review to identify and eliminate unnecessary regulations that kill jobs and bloat government," the transition team said last month.