[Lintelyg]

Why there is hatred is for the gods to know.
My own theory in this is this:

Orcs will kill humans and Elves etc. because they are monsters, right? They hate each other because their cultures are different. Besides the hate isn't absolut. There are half-orcs right? Back to the point: Can you imagine gnolls and humans living together peacefully? Gnolls being the fierce creatures that they are will rather go for force than asking, because that's how it works in their group. Also fights between certain tribes of orcs and gnolls against humans can be started out by pure necessity. Like food. The monsters are also thinking, never forget that. They don't purely act on instinct, so if humans are moving in on territory they will defend it with their lives. Get it??? ;-)))

Now wyverns:
A wyvern is a relativly small creature compared to it's dragon cousins. In my experience have mostly been held by mages and sorcerors as pets. They are aggresive and territorial, i think. If not held captive, i guess they would be a wild beast. Thats all i can say bout that.