Frank Heffley

Frank Heffley is a major character in the Diary of a Wimpy Kid series. He is Greg's, Rodrick's, and Manny's unpredictable and serious father. He is the husband of Susan Heffley (Greg's mom) and the brother of Uncle Joe.

Personality
Frank is over-possessed, disciplinary, argumentative, critical, over-reactive, shrill, irritable, strict, insecure, easily-bothered, ill-tempered, shallow, and emotional. He is constantly bothered and troubled by such small matters, such as Rodrick's typing skills and Greg's silly mistakes, and always wants his sons to look good in front of his boss, a very small matter that Frank constantly gets worked up about; this shows that, like his son, he is shallow and worries about what other people think about him rather than what he thinks about himself. He is very serious and over-possessed in the fact that if his sons do something that irritate him ever so slightly, it makes him become incredibly serious and critical of their behavior. He is a hard worker, and has a poor relationship with all of his sons, since the three cannot relate to each other at all in any way possible, nor can they relate to Frank himself.

Interests
Frank has a very strong interest in American history, proven by the fact that he builds a Civil War battlefield in his spare time. He does not let anybody into the furnace room where the Civil War battlefield is housed, as he is extremely cautious about what he lets people do to his battlefield as he thinks it can be easily ruined.

Dislikes

 * Heavy-metal music - Frank utterly hates this genre of music, since it drives him crazy.
 * Video games - Frank thinks that video games are simply a subject of distraction that prevents Greg from doing exercise.
 * Rowley Jefferson- Frank thinks that Greg's best friend is "accident prone."
 * Teenage delinquents- Frank finds teenage delinquents as a complete source of trouble.
 * His younger brother - Prior to the end of The Ugly Truth, Frank found his brother as a huge troublemaker that always causes some sort of trouble with his family. At the end of The Ugly Truth, they are apparently getting along again.

Appearance
Greg's illustrations depict Frank wearing a tie, and a few strands of hair falling down in his face. Sometimes, Greg illustrates his father wearing shorts, but this is only when his father goes to bed.

Greg Heffley
Greg and Frank, overall, have a terrible relationship. In Diary of a Wimpy Kid: The Last Straw, Frank gets fed up with Greg's behavior and threatens to send his son to a military academy to toughen him up simply because Greg did not live up to his expectations. Greg tries to circumvent this by proving to his dad that he does not deserve this treatment by "doing his best" in soccer and joining the Boy Scouts, among other things, but ultimately fails to impress his father. It is not until Seth Snella's half-birthday party that Frank realizes that his son's wimpiness is a good characteristic, because it saved himself from looking foolish in front of the entire town. It is in Dog Days where their relationship completely breaks down; Greg's paranoia got them in trouble with the police. Based on the fact they are seen together later in the book insulting the first edition of the new Lil' Cutie comic strip, the conflict, however, may have at least partially cooled off to the point that Greg realizes that things will be okay with his father.

Rodrick Heffley
Rodrick and Frank, like Greg and himself, have a terrible relationship with one another. However, unlike the relationship between Greg and Frank, this relationship is much more volatile. Frank has shown no love for his eldest son, and is bothered by his poor effort at school, his poor typing skills, and most of all, his lack of focus on education. Despite this, however, Frank had never tried to help Rodrick change in a fatherly manner. The only thing he does is scold him and forcefully enroll him in classes. According to the second book, Frank would be very happy if Rodrick moved away. This relationship proves Frank is hypocritical.

Manny Heffley
Even though Greg assumes that his father spoils Manny as much as he thinks him to do, Frank does not spoil Manny, and he has no existent relationship with him. In The Last Straw, Frank throws away Manny's blanket Tingy and Manny retaliates by vandalizing his Civil War battlefield, implying a tense relationship.

Susan Heffley
Frank and Susan have a good relationship, though Frank doesn't seem to like some of her traits. For example, he completely doesn't seem to like the fact on how she encourages father-to-son bonding, which Frank finds rather awkward, since most of her plans to show affection with Greg and Rodrick end up disastrous.

Grandpa Heffley
Frank and Grandpa had no distinctive relationship until the fourth book, in which they now have a tense relationship. Frank had a rather minor role in the fourth book until Father's Day, where Grandpa admits that he lied to him about his dog, Nutty, running off to a "butterfly farm", and instead admitted that he accidentally killed his dog. Frank, in a very immature manner, becomes furious and decides to buy another dog to make up for the lost one. This dog was named "Sweetheart" much to the three siblings' dismay, or Sweetie for short. Frank becomes obsessed with this dog, even though Sweetie is two times as lazy and repulsive as Greg. In the online book, Frank overreacts to the fact that Grandpa killed his dog even more, and goes as far as to reject his cake and lock him outside their house in the night by himself.

Uncle Joe
Frank has an ongoing rivalry with his younger brother. His younger brother has caused a lot of trouble to Frank's family, such as preventing Manny to go to the toilet. His younger brother is also very immature and never listens to his older brother, as shown in the second book, where Joe claims that Frank's hard-worked Civil War battlefield are mere toys. However, in The Ugly Truth, Frank and Joe are apparently starting to get along again.

Rowley Jefferson
Like how Mr. Jefferson dislikes his son Greg, Frank doesn't seem to like Rowley at all. As Greg states, Frank hates him because he finds Rowley "accident prone" because Rowley has caused damage to the Heffleys' property. This results in Frank thinking too deeply about it and coming to the conclusion that Rowley will completely ruin his Civil War battlefield. As such, he does not allow Rowley to go into the basement, where his Civil War battlefield is set. He is so paranoid that he usually greets Rowley in a rude manner, telling him the basement is off limits rather than being polite, which Rowley calmly responds to with a "Yes sir.". They do not interact at all in "Dog Days" or "The Ugly Truth", however, and Frank may be more accepting of Rowley due to the latter maturing.

Trivia

 * Frank's actual profession is not listed so far. Greg, however, does know what his father does for a living. Apparently, it may be hinted that Greg has no intention of telling what he knows.
 * Frank is a junk-food addict, therefore implying that he may have a high cholesterol level. This is rather ironic as Frank is not depicted as overweight.