Dr. Diaper's Robots (or Dr. Nappy's Robots in UK versions of the Captain Underpants books) were robots that were created by and worked for for Dr. Diaper. They are the secondary antagonists of the first book.
While George Beard and Harold Hutchins were chasing Captain Underpants through Piqua, these robots stole a crystal at a jewelry shop for the Lasermatic 2000 to work. They went in a van and Captain Underpants' cape got stuck on the van's door with George Beard and Harold Hutchins hanging on. They stopped at Dr. Diaper's warehouse and the evil team captured Captain Underpants. Dr. Diaper initiated the Lasermatic 2000 to destroy the moon and revealed it would be finished in 20 minutes. George and Harold shot a piece of fake dog doo-doo near Dr. Diaper, causing him to temporarily leave to change. The robots saw George and Harold and attempted to kill them, but failed miserably and were destroyed.
- They are the first antagonists to appear in the entire series, not counting the fictional Inedible Hunk.
- They are also the first characters to be killed.