When it comes to the pokemon biology, We already witnessed and known in the game that Zangoose and Seviper are mortal enemies. What is there are more among different kind of Pokemon that are considered mortal enemies. What if Cacturne have another cactus pokemon around and react to its presences? What if scorbunny has sort of fire pokemon that has a grudge against it? The list goes on as the mysterious world of pokemon has its fair share of friends and foes.