Manny is the younger brother of Greg and Rodrick Heffley; a ridiculously-pampered, annoying, obnoxious, Spoiled-rotten toddler who is constantly being doted on by his mother. He has a great number of demands and requests, and will throw temper tantrums if these wishes are not fulfilled and he is extremely self-absorbed in spite of his young age. Among Manny's most well-known character hallmarks are his refusal to be toilet-trained and his complete inability of entering a nursery school in which he can remain. Despite his very young age, Manny has shown signs of actually possessing more intelligence than he seems to; he managed to keep the electricity turned off in every room of the house with the exception of his own in "Cabin Fever" and it was in this same book that he successfully managed to change the password to Greg's account on a gaming website. He also has been shown to frequently damage the property of his older brother Greg, as seen in a number of books, and the excessive coddling that he receives from his parents infuriates Greg deeply. In Cabin Fever, it was found that when Manny is scared, he hides in his sock drawer.