The first prototype of the Supermarine Spitfire was called "Shrew" by its designer, and it was proposed to be an official name for the plane. However, the Ministry of Defence opted for "Spitfire" instead.
Supermarine based it design for the Spitfire fighter plane on its earlier seaplane racer which competed for the Schneider Trophy before the war. [On the Axis side, the Macci Folgore was also based on their Schneider entry, but I am presuming the question is about the famous Allied fighter plane.]
The possessive form of 'the wingspan of the fighter plane' is the fighter plane's wingspan.
P-38 Lightning
The P-51 Mustang was possibly the most famous American fighter of WW2. I don't recall any gun of this same name.
Their most famous airplane was the "Zero" Fighter; A6M5 Zero, the word "Zero" indicating the number "0" as that was the year the fighter plane was adapted by the Imperial Navy in 1940.
The P51 mustang was a famous fighter used by the allies in World War Two.
Form of a fighter plane is purely dictacted by function.
There is no Seahawk Fighter Plane yes there is, but no it cant.
T I E = Twin Ion Engine
The main function of the fighter plane was for air-to-air combat against other aircraft. The hallmarks of the fighter plane are its speed, maneuverability, and small size relative to other combat aircraft. The main objective of the fighter plane is to establish air superiority.
The first operational fighter plane was the Vickers F.B 5 "Gun Bus".
Who is to say what is the "world's best fighter plane" - there are many criteria to judge this by.