Over the years, Donaldson has gained a huge following by creating viral videos and performing stunts for his YouTube channel.
These have escalated into huge, high-stakes problems in which he gives away large sums of money to strangers.
He also helped create the Prime Video reality series Beast Games, inspired by the hit Netflix show Squid Game.
It follows contestants as they play a series of games in the hope of winning a $5 million (£3.7 million) prize pool.
Booysen, who is originally from South Africa, also has his own channel on the site, TheaBeasty, which has nearly 140,000 subscribers.
The 28-year-old also streams games on Twitch and is a published author.
Donaldson’s rise to fame as the most successful YouTuber has not been without controversy.
In April, media company Beast Industries, owned by MrBeast, was sued by a former employee over allegations of sexual harassment and gender bias in the workplace.
He is also facing a lawsuit from Beast Games participants over how they were treated, and claims his viral pranks and competitions were orchestrated and pre-planned.