Adult Dib is the name fans have given to a background character that appears to be an older version of Dib, albeit with a backwards scythe hairstyle. He is not to be confused with the older Dib that appeared in Dib's Wonderful Life of Doom.

Adult Dib made a cameo appearance in Attack of the Saucer Morons, and has only appeared in one other episode: Mysterious Mysteries. He only had one line throughout the series: In Attack of the Saucer Morons, after having his head bitten down on by the pig, he said, "The pig accepts me!" He was seen again in Mysterious Mysteries communing with the Blotch with the rest of the Children of the Bright and Shining Saucer.

He was voiced by Rosearik Rikki Simmons, though it is hard to tell, because his voice was muffled at the time. It is also unknown as to whether Jhonen Vasquez intended for him to be related to Dib or not.