Mr. Sandoval is a resident of Greg's neighborhood who only appeared in Hard Luck. When it was snowing, he put two poles to mark the pavement so that the man who plows it know where the mailbox is. One day, Greg and Rowley plucked out the poles and started playing with them and later put them about 10 feet away from where they originally were. This made Mr. Sandoval angry and according to Greg, until this day, Mr. Sandoval is waiting for Greg and Rowley to show their faces, and because of that, Greg would cover his face whenever passing by his house.
- Diary Of A Wimpy Kid: Hard Luck (First and only appearance)