Mark Cuban has offered Donald Trump $1 million to shave his head.

The multimillionaire owner of the NBA's Dallas Mavericks bet Trump to do so after Trump offered $5 million to President Barack Obama in October if he released documents to prove he was born in the United States.

"The offer he made for five million, that was one of the dumbest things ever," Cuban told TV station KDFW.

"Donald, you shave your head, $1 million to any charity you want," Cuban said on Fox 4 News.

Cuban even threw in an additional million, to make the offer a $2 million charity donation if that would sweeten the deal for Trump.

The Huffington Post reported that Trump has yet to reply to Cuban's offer.

Trump announced late October that he would give President Obama $5 million to a charity of the president's choice only if he revealed his college transcripts and passport records by the end of the month. The offer, which ended this week, went without any comment from president Obama.

"Obviously [the president] wasn't born in this country," Trump claimed on Thursday.

"Or, if he was, he said he wasn't in order to receive financial aid and in order to have a clear and very easy path into a college for university," Trump continued.

"Only a very stupid person would believe otherwise."

Meanwhile, Cuban isn't the only person who is annoyed by the wake of Trump's $5 million offer.

On Oct. 25, Barbara Walters called Donald Trump out on The View. She spoke regarding his offer to the president and told him to stop making a fool out of himself.