Jean Havoc

Second Lieutenant Jean Havoc is one of Colonel Mustang's most trustworthy subordinates at the Eastern Headquarters and one of the few privy to the Colonel's goal of becoming Führer. A self-proclaimed 'country boy', Havoc is usually rather laid-back and almost never seen without a cigarette in his mouth, but is an honest, loyal and hard-working soldier who leads his own subordinates by example. Although not the most intelligent, Havoc more than makes up for his simplicity with common sense and cleverness - often providing a sarcastic, real-world perspective to counter the over-the-top antics of his comrades - as well as a particularly high combat aptitude. But the fair-haired son of eastern Amestrian merchants does have a noteworthy weakness: throughout the series Havoc's poor luck keeping a girlfriend plays a recurring theme, as shown when he is forced to leave a new relationship in East City when being transferred to Central with Mustang and when he is spurned by Major Alex Louis Armstrong's younger sister Catherine Elle.

2003 anime series
In the 2003 anime series, 2nd Lt. Havoc plays little more than a supporting role in the storyline, providing comic relief and backup alongside his comrades Heymans Breda, Vato Falman and Kain Fuery. Notable instances of Havoc's involvement include the point at which he and Master Sergeant Fuery are lightly wounded by ricochet fire while attempting to sneak up on Edward and Alphonse Elric near Resembool and his mission, near the end of the series, to act as a decoy for the Amestrian Military by disguising himself as Mustang during the Colonel's coup in Central City.

Manga
In the manga, however, Havoc plays a more significant role in the story, beginning in volume 9 with the Barry the Chopper mission to lure out the Homunculi.