Promo clips such as the one above show Rosolie putting on a special, and presumably protective, suit.
"You have to go head first," Rosolie says in one of the clips.
He's also tethered to something as he approaches the snake. Since the show has already been filmed and Rosolie has been active on Twitter, it's a safe bet that he is pulled back out again.
But some viewers are concerned about the fate of the snake, and are already protesting the show. There's even a petition on Change.org calling on Discovery to pull the plug.
"This is animal abuse to the highest degree and absolutely disgusting, and could kill the snake," the petition reads. "An adult green anaconda cannot fit the width of an adult man's shoulders into it's body."
Rosolie defended himself and the show.
"I understand that many people have questions," Rosolie wrote on his website. "All I can tell you now is that all my work is based around the fact that wildlife and ecosystems today, across the globe, are at a critical moment."
He said snakes are being threatened by hunting and habitat destruction.
"For those worried about animal cruelty, I invite you to research my work -- read my book," Rosolie added. "Then ask yourself: would this person ever hurt an animal?"