Nicknamed "the Crocodile" for his ruthlessness, Emmerson Mnangagwa who took over Friday as Zimbabwe's president, is a hardliner with ties to the military who could prove as authoritarian as his mentor Robert Mugabe.

It was his driving ambition to take over as leader which set off a bitter succession battle with Mugabe's 52-year-old wife Grace, triggering the crisis that toppled the long-serving president, who resigned on Tuesday.

When Mnangagwa was dismissed as vice president by Mugabe on November 6, it initially looked like he'd been outfoxed by the first lady, forcing him to flee the country.