Fanon Pokedex: Fighting Type
Named for their prowess in Martial Arts, Fighting type Pokemon are incredibly potent battlers who specialize in physically disabling their opponents. They constantly seek new challenges and worthy foes, often finding a position defending some area or in competitive combat. A large number of them have a sense of honor, as they will not assault the helpless and in fact will go out of their way to assist injured comrades. Quite notably, a number of Pokemon can learn Martial Arts as they evolve, thus making Fighting Type a mostly secondary hybrid (though exceptions exist).
Fighting Types are experts in finding weaknesses in opponent's bodies and assaulting such nerve points with precise movements. This not only devastates normal types as well as the fragile Ice types, but makes the normally impenetrable bodies of Rock and Steel types work against themselves as the Fighting pokemon will make their eponymous armor collapse upon the user and often dodging Rock type assaults. The level of mental training Fighting types have also allows them to predict the feral mindset of Dark type pokemon, giving them both offensive and defensive advantage.
For all their advantages, however, Fighting Types are still susceptible to the mind-reading abilities of Psychic types, who avoid their attacks and mercilessly assault the structured minds they have. Fairy type pokemon are also capable of surprising determination against fighting types, allowing them to power through attacks and land dangerous hits. Flying types also use their aerial maneuverability to evade and harass fighting types, which has caused more then a few incidents of fighting types declaring all birds evil. Their reliance on physical maneuvers makes ghost types invulnerable to their attacks, and they tend to reduce their power deliberately against Poison types in order to avoid being, well, poisoned. Their usual methods also cause confusion with the Bug type, whose bodies are usually quite different then other species; fortunatly, the bugs have an equally hard time adapting their own methods to a martial artist that can dodge their stings.
With the sole exclusion of the legendary Musketeers, all fighting types are roughly humanoid. This makes sense, as a bipedual stance typically gives a pokemon a firm sense of balance from which to unleash a barrage of punches/karate chops/kickboxing/what have you. Some proponents of the "pokemon-descended humanity" theory believe humans were originally Fighting type pokemon for this reason.
While there are a few herbivorous species, the sheer energy required to substain martial arts activities makes most fighting type pokemon omnivorous if not out right carnivores.
Due to their obsession with martial arts and physical prowess, most fighting type pokemon engage in ritual combat for mates.