Franky's dream is to build a ship that would travel to the end of the Grand Line. This is the ship that the Straw Hats are currently riding, but his dream is not yet achieved until they make it to the end.
Franky usually acts tough, and is quickly angered, but he is sensitive and emotional to sad tales or tales of honor. Hearing such stories causes him to burst into tears or play songs on his guitar. When in tears, he will unconvincingly deny that he is crying. His most distinguishable personality trait is his flamboyant attitude. He frequently shouts the word 'SUPA' when he's in a positive mood, or adds it into his speech. He also has a signature pose which he uses very often, and performs odd dances when large crowds are focusing their attention on him, such as during his fights and robberies as the head of the Franky Family. He also has an outlandish style of dress, consisting of only a Hawaiian shirt, dark blue speedo, sunglasses, and a huge gold chain.
Franky is strong-willed and free-spirited with an often blatant disregard for rules. He does whatever he wants whenever he wants, though he usually wants little more than to build powerful ships or protect those he cares about. Quick to defend other people and take action if his friends are harmed, he also holds the belief that no matter what a person is like they should never be prejudiced or exterminated simply because of who they are. This often causes him to befriend and defend the wrongfully feared and persecuted. Because of his unbiased and protective attitude, he is quick in making friends and allies with even (or especially) the most unlikely of individuals, such as street thugs and pirates. He is seen as a 'big brother' figure, and is admired by many for his efforts to protect them, such as [Nico Robin] and the Franky Family. [Monkey D. Luffy] bears similar qualities (with the exception of engaging in unnecessary fights) and because of this, despite the disputes the two had in the past, both grew to respect each other during the events of the Enies Lobby Arc.
Franky's real name is Cutty Flam (カティ・フラム, Kati Furamu). When he was young his parents (who were pirates) threw him off their ship into the ocean. He was then rescued by a legendary shipwright named Tom. Tom took Cutty Flam in as his apprentice. Tom's other apprentice Iceburg then gave Cutty Flam the nickname "Franky" because "Cutty Flam is a weird name".
Some common attacks include Strong Right (Franky launches his right fist forward and can reel it back in with a chain, similar to Luffy's Gomu Gomu no Pistol) and Coup de Vent (Franky connects his arms with a T-shaped pipe and sends a powerful blast of concentrated air out that can destroy entire buildings, his most powerful attack that uses up the most cola). Franky also has the power to turn into a centaur-like form (with an extra set of legs strangely extending forward from his pelvis), though he has implied that its use is limited by stating he is "super powerful this week" just before he uses it. Despite his pride in it, it seems to do relatively little for any of his combat abilities, save for using his four legs to trap his enemy's limbs, leaving them completely at the mercy of his attacks.
Depending on what kind of drink Franky has as his fuel, his hair style and attitude can vary, revealed when Chopper accidentally hands him vegetable juice and tea. It is also revealed that Franky's strength and weapons are many times greater when he has cola in his stomach fridge, and he needs it as a fuel for some attacks, particularly his ranged weapons. His hair acts as a kind of meter to the amount of cola in his stomach being tall if he is full and sagging if empty. Franky's stomach compartment can hold up to six bottles or six litres of cola. Residing several years in Water 7's back alleys resulted his unorthodox fighting style, where he prefers to fight head-on and shows no regard whatsoever in the traditional ethics of fighting. If needed, he can use his incredibly durable body to block incoming head-on attacks from adversaries, a common tactic. Another common tactic is to use his trash-talking to provoke his opponents into unwisely attacking him.
Also, as a shipwright, his building capability is top notch; aside from building Strawhat's Thousand Sunny, Franky is able to build a very stable bridge across a large gap in an instant, using only the debris nearby (while also paying amazing attention to detail). (chapter 461) As of now, it would seem that Franky's right hand is for physical attacks and his left hand is for weapon-based attacks.
Franky's weakness is his back: When he built his cyborg parts, he was unable to reach around to his back, and thus, there is no machinery in that part of his body. Because of this, Franky's back can be hurt there by something as small as a needle while the front of his body can take bullets and bombs without so much as a scratch.