There is another unborn son of Greg Heffley shown in Hard Luck, and he is about 6-8 years old by how he looks, when he explains that he thought that he would end up in a good relationship unlike Rowley. He looks identical to Greg's younger self. There also another who looks like a new-born baby and he also has a daughter.
- Even though Greg fictionally explained he would be 95 at time, his son looks quite young. His son should be 40 years old by then. Or else it is possible that it is his grandson, which would be more logical, referring to him as "Dad".
- Its unknown whether he will actually exist or if its only Greg's imagination..
- His younger unborn son is named Greg Jr..