That's L.J. Gibbs(:

Gibbs' age has never been revealed, but it was shown in the episode "Heartland" that he was born in rural Stillwater, Pennsylvania. His father, Jackson Gibbs (played by Ralph Waite), owns a store ("Stillwater General Store") in the same town. It has been mentioned in the episode "Frame Up" that Gibbs' father was possibly in the United States Army Air Force because Gibbs refers to a pin-up on his father's P-51 Mustang. He is named after his father's friend, Leroy Jethro, who was his business partner in the store after having worked together in the coal mines (Winslow Mining Company). The younger Gibbs left Stillwater in 1976 at the approximate age of 18-20 and, according to his own statements, did not return for over thirty years. In a flashback seen in the episode, Jethro often provoked violence with defiance to his father, who constantly comes to his unwanted aid with a Winchester rifle or shotgun. He was also known around the area as a delinquent, as said by the new sheriff, one of the other delinquents during his teenage years, stating "Funny, never expected to find you on the same side of the law."
A former MarineScout Sniper and Military Police NCO, Gibbs is portrayed as a consummate organizer, disciplined and demanding. These traits often put him in a stand-off with other authorities when they exert pressure on his team. In the JAG episode "Ice Queen", it is stated that he is a Marine reservist. Although he has not served as an active Marine in some time, he retains enough of his marksmanship skills to kill Ziva's captors in the premiere of season 7, "Truth or Consequences," and to out-shoot a professional hit-man in "South by Southwest."
In "Under Covers," Abby Sciuto wishes him "happy birthday" on November 10, referring to the Marine Corps birthday.
Before the time in which NCIS is set, Gibbs travelled extensively on operations, particularly in Eastern Europe, demonstrated by many flashbacks, many including Director Jenny Shepard. 
Gibbs has been married four times, and divorced three; his first marriage was kept a secret from nearly everyone of Gibbs' acquaintance until the episode "Hiatus (Part 1)". The first hint of Gibbs' first family is when he asks Ziva if she's prepared a dossier on him, and does she know of his "first wife and daughter." She answers "Yes." The viewer is shown a glimpse of Kelly several episodes later, in a flashback just prior to the credits, after having spent the day bonding with a brilliant, disciplined, (even "Gibbs-like" Abby said) 5-year-old son of a kidnapped officer. In the episode "Heartland", it is revealed that Gibbs met his first wife, Shannon, while waiting at the Stillwater train platform in 1976, at which point she tells him about her rules for life; these rules would inspire a similar set of Gibbs' own that he now teaches to his subordinate agents at NCIS. Shannon, along with their eight-year-old daughter Kelly (seen working with him on his boat in a flashback at the end of the episode "Honor Code"), were murdered by a Mexican drug dealer named Pedro Hernandez on the last official day of Operation Desert Storm (February 28, 1991*); Gibbs had been an active member of the Marine Corps at the time and was still overseas when they were killed. Gibbs later killed Hernandez. According to the pilot episodes of NCIS: Los Angeles, Gibbs was suspected and, in fact, investigated in connection with Hernandez' murder, but the agent leading the investigation, Lara Macy, decided not to prosecute despite sufficient evidence, as she considered the killing justified. However, in the NCIS episode "Borderland", an unknown conspirator manipulates events so that Abby ends up investigating the murder as a cold case and finds irrefutable proof that Gibbs is responsible. Despite this, she is conflicted on whether to drop the case or pursue it. Lara Macy was found dead in the episode "Patriot Down".
One of his wives, Diane, later married Gibbs' friend FBI Senior Special Agent Tobias Fornell (Joe Spano); Fornell later admitted to Gibbs that the marriage was "the biggest" mistake of his life. Gibbs' wife Stephanie Flynn (Kathleen York) lived with him during his service in Moscow, Russia for about a year. Each wife was a redhead like Shannon.
Even pathologist Dr. Donald "Ducky" Mallard and Director Shepard, who had known Gibbs for many years longer than the rest of his team, had not been informed about Shannon until they discovered the file about her murder during Gibbs' coma in "Hiatus". Ducky claimed in the episode "Mind Games" that Gibbs' wife found it impossible to stay in their marriage when Gibbs was originally hunting serial killer Kyle Boone, but which wife he was referring to was never specified. According to Gibbs she was the one who left him. N.B.: The temporary internment markers seen in Gibbs' flashbacks during "Hiatus", as well as the dates of death in the NCIS files on their murder places the actual date of Shannon and Kelly Gibbs' death as February 29, 1991 Gibbs also once had a romantic relationship with the (now deceased) director of NCIS, Jenny Shepard, who was also a redhead. In the first, second, and once during the third season, he was seen in the company of a mysterious (and never-identified) redheaded woman.In season four, he had a steady, serious relationship with Army CID agent Lt. Col. Hollis Mann, curiously not a redhead, but their relationship ended at the beginning of season five, when it was revealed that she was retiring to Hawaii.
After Shannon's and Kelly's death and before he remarried to his second wife, Gibbs is suggested to have had an affair with a woman in Colombia, named Rose. He was on a drug interdiction mission as a Marine Scout Sniper, and was wounded during the mission. In the episode this is revealed Rose's son is introduced as a person of interest in a case after Gibbs' Marine service number was found written in blood at a crime scene. Gibbs was suspected (by his team) of being the boy's father; but Gibbs later reveals to Rosa's son that she was already pregnant with him when he came to their village, but leaves out that the drug lord Gibbs was sent to assassinate was, in fact, the boy's father. In Season 7, Gibbs meets lawyer Margaret Allison Hart who was sent by an old enemy that Gibbs had locked up in a Mexican prison. Though they oppose each other over many cases, they are also attracted by one another. In the end, when it turned out Hart's boss was responsible for the death of Lara Macy in connection with the murder of Pedro Hernandez, Hart turned her back on him, showing that she cared more for Gibbs than for her boss. She later prevented the report incriminating Gibbs for Hernandez's murder from reaching Mexico and gave it to him.
Gibbs displays a continuous urgency about the investigation he pursues, specifically when being given technical information about complex subject matter. The typical response to such information is "Give it to me in English", thus forcing the expert to get to the point, as well as making it easy for the audience to understand. He also displays elements of sarcasm particularly in relation to someone in his company stating something obvious. The typical sarcastic answer "Ya think?" is his preferred retort. He displays a degree of impatience toward high-tech hardware, as in the Season 4 episode "Witch Hunt" when he stomps a Roomba to pieces in order to prevent it from vacuuming up evidence at a crime scene.
When he thinks it absolutely necessary, he will turn over command of the team to one of his agents, as seen in the Season 6 episode "Bounce." Here, the murder of a Navy officer has apparent connections to an embezzlement case handled by Tony DiNozzo years earlier, so Gibbs trades places with him while citing "Rule #38 - Your case, your lead." The two resume their normal roles by the end of the episode. On rare occasions, if the usual judicial process is incapable of bringing a suspect to justice, he will turn a blind eye and allow "street justice" to run its course. One example occurs in the Season 3 episode "Iced," when a street gang member suspected of killing three of his subordinates must be released for a lack of evidence. Gibbs drops him off on a street corner where he runs into several angry gang members, who have learned of the circumstances through a visit to the NCIS morgue; the team later sees a TV news report that the suspect has been shot dead, but Gibbs suggests that they stop watching and get back to work.
He is a dedicated coffee drinker,[9] a fact played out with his team setting up someone to innocently drink or spill his coffee, incurring Gibbs' ire. In the episode "Forced Entry", when McGee unknowingly drinks Gibbs' coffee, an on-base security officer explains that rule #23 is "Never mess with a Marine's coffee if you want to live." At episode's end, Gibbs endows McGee with a cup of coffee as a thank you. In the episode "Hiatus (Part 1)", Ziva claims that if Gibbs had been killed in the explosion on the ship, the color of his guts would "be more coffee brown than red."
However, only twice had Gibbs dropped his coffee of his own volition, both times when forensic scientist Abby Sciuto was in serious danger. The first time was in the episode "Kill Ari" when a sniper (Ari himself) shot into Abby's forensic lab, the second was in the episode called "Driven" when Abby was nearly suffocated by exhaust in an experimental humvee. Aswell on one occasion Gibbs gave his current cup of coffee to Abby when she was in caffine withdrawl from trying to give up caffeine.
Gibbs has a very close relationship with Abby. He is extremely protective of and comfortable around Abby, often massaging her shoulders, and kissing her cheek when she does especially good work. He usually looks the other way in her style of dress and her quirks, because he knows that she does her job very well. He also brings her her favorite caffeine beverage, called Caf-Pow. On several occasions, Gibbs admitted Abby is his favorite.
His hobby is woodworking. Gibbs is shown to always have a wooden-hulled sailboat under construction in his basement, which he builds entirely by hand using no power tools. In the episode "Tribes", he tells FBI Agent Langer: "Finished it twice. This is number three." He later tells NCIS Director Jenny Shepard that he is working on his fourth boat, and that he named one of the previous boats after his (then current) wife when he finished it, then burned it after their divorce. When asked why he didn't simply sell it, Gibbs replies that he "couldn't stand to see someone else sailing Diane." Dr. Mallard tells Colonel Mann that another of Gibbs' boats was named after his daughter, Kelly. It is not revealed what Gibbs did with the other completed boats, nor how he could remove their twenty five foot hulls intact from his basement. When asked by McGee, Gibbs cryptically replied, "Just break the bottle." In the episode "Honor Code", when Gibbs is talking with a Lt. Commander's son, he does mention a possible method which would involve taking down part of his wall and hauling it out through the now wide enough space, thus breaking the bottle.
One of Gibbs' "trademarks" is that he will often slap the members of his team on the back of the head when displeased with their performance, though he does this mainly to DiNozzo as opposed to other members. When Gibbs "retired", and Tony gained his position as leader for a short while, Tony often slapped the team members in a similar fashion; in the episode "Hiatus (Part 2)", Mike Franks is shown slapping Gibbs in the same manner in a flashback. As revealed by Ducky in the episode "Mind Games", about ten years earlier he was just like Tony. When asked why he slaps his team only on the back of the head Gibbs responded, "A slap to the face would be humiliating. Back of the head is a wake-up call." At one point he also threatens to slap Abby, though not on the head. In the episode "Family Secret", Gibbs even slaps his own head for breaking chain-of-evidence rules.
When somebody mentions the loss of children and wives, Gibbs rarely comments although he may react slightly. When Caitlin Todd was killed, Ducky, who at that point did not know of Shannon and Kelly's story, mentioned that Ari was targeting women and neither of them (Ducky or Gibbs) has ever lost a loved one, Gibbs paused and didn't say anything.
In the episode "Faking It", it is revealed that Gibbs speaks Russian, and he at least speaks a little Japanese and Chinese ("Call of Silence" and "My Other Left Foot", respectively). He also signs American Sign Language, which appears in many episodes in conversations with forensic scientist Abby Sciuto.
In the episode "Heartland" it is revealed that he had bought a 1970's Dodge Challenger R/T which he planned to restore, but never did. Later in the same episode it turns out that his father had restored the car the way Gibbs wanted it. The car was yellow with a black bonnet stripe and was stated to have the 426 HEMI and R/T suspension package. He drove the car with a smile on his face, first time out. Before the Dodge Challenger, Gibbs drove a Ford F-150 as shown in Shalom.