Leonardo DiCaprio and Robert De Niro are offering a walk-on role in their new movie to a fan who donates to a new celebrity-driven Covid-19 fund.
People who give to the All In Challenge will be entered into a prize draw.
The campaign was launched on Tuesday to help feed vulnerable people in the US and has already raised $5.6m (£4.4m).
Ellen DeGeneres, Kevin Hart, Justin Timberlake, Justin Bieber and many US sport stars have also offered donors a chance to get up close and personal.
Bieber has promised to fly to one lucky fan's house - once the lockdown is over - for a private performance of his 2009 hit One Less Lonely Girl.
Hart has offered a speaking role in his next movie, while Timberlake and Bill Murray will give a winner a round of golf.
Matthew McConaughey has invited a donor to join him in his private box to watch an American Football game in Texas.
DeGeneres and wife, actress Portia de Rossi, will donate $1m (£800,000) and offer a donor the chance to co-host an episode of her chat show.
DeGeneres and McConaughey were both nominated to take part in the challenge by DiCaprio, who himself is offering a fan the chance to hang out on the set of Killers of the Flower Moon with him, De Niro and director Martin Scorsese.