Elon Musk is a wild card who could make life difficult for Twitter's new CEO

In the last two years, Twitter has dealt with an activist investor, an egocentric figure with tens of millions of followers pushing the limits on its platform and an eccentric billionaire leader attempting to improve the product while juggling multiple companies.

Now, Twitter appears to have all three at once, in one person: Elon Musk. The Tesla and SpaceX CEO sparked a deluge of headlines this week after disclosing that he'd become Twitter's largest shareholder. A day later, the company said it would add him to its board of directors for a two-year term.

These stunning developments put Twitter, a company that is certainly no stranger to corporate chaos, in uncharted waters. Suddenly, the world's richest man, who is known both for his ambitious and innovative spirit and for his erratic and trollish behavior, has a powerful seat at the table. And he's coming on board just as Twitter's previously little-known (at least externally) new chief executive, Parag Agrawal, attempts to come out from the shadow of Jack Dorsey, the platform's founder and longtime public face. Dorsey, who handed over the CEO role in November and plans to exit Twitter's board in May, said this week Agrawal and Musk "will be an incredible team."