Rowley Junior was the egg-version of Rowley in The Ugly Truth, when Nurse Powell gave every kid eggs and told them to bring them the next day without breaking them. Greg and Rowley were the only boys who didn't break their eggs. However, Greg's egg was accidentally cooked for breakfast by Susan. So, Greg tried to swipe Rowley's egg and pass it off as his own, but by the time he tried to, Rowley had already drawn a face on it, making Greg have nothing to pass in. Later, Nurse Powell congratulated everyone who kept their egg safe and chucked them all in the bin, including Rowley Junior.
- The egg had seven strands of hair and round eyes and a mouth, like Rowley. A bow tie was also part of its appearance. It was made to resemble Rowley. He was heartbroken to find out that Rowley Junior had been thrown away.
- There is also a game based on the egg called Don't Scramble the Egg.
- One of the "That's you" drawings in Rowley's journal depicts him as a broken egg. This could be a reference to Rowley Junior.