Green was initially thought to be an invisible ghost by Sammy, the protagonist. However, in the twist ending, it's revealed that he's actually a human boy who was somehow made invisible by his mother, so he would survive in a world now inhabited by aliens (including Sammy and his family).
Brent Green appeared in the television adaption of My Best Friend is Invisible, portrayed by Darcy Weir. At the end of the episode, Sammy and his parents surround Brent menacingly, presumably with the intent of killing him.
Brent Green appears in the 2015 Goosebumps film voiced by Jack Black, but referred to and credited as the Invisible Boy. He suddenly appears on the the windshield to R.L. Stine's car leaving noticeable hand prints. He climbs around the car and hits Champ in the face. Stine removes him by accelerating the car really fast then comes to an immediate stop flinging him from the car. He replies by shouting "Not cool!".
At the end of the film, he reveals to Stine that he somehow evaded getting captured by beginning a story titled The Invisible Boy's Revenge on Stine's typewriter and leaves hand prints on the trophy case as he tells Stine, "You forgot about me!" Stine screams in horror as Brent's hand print appears on the cabinet glass while Brent maniacally laughs. The image is then turned into a book cover with the tagline "Invisible but deadly."
Some see the Invisible Boy not getting sucked up by the book as a plot hole, due to Zach Cooper writing "all the monsters go back into the book." However, there are some theories to combat this:
- Because Green was last seen on a lone road, and may have been still there when Zach finished the story, Green may have been out of the book's range.
- More plausibly, assuming he was still on the road and further from the rest of the monsters, he may have needed more time to be absorbed, but Zach closed the book before Green could be absorbed.
- Green, as an invisible human boy, may not have counted as a monster in Zach's eyes and, as such, was never targeted for absorption.
- According to Stine, he needs to write a real Goosebumps story in order for the monsters to be sucked back in. Since Goosebumps stories usually include a cliffhanger and a twist, having one of the monsters be still out there would work as a twist.