As a sabertooth cat living in Kunark, life is much harsher. In this world only the fittest survive, so with the stronger sentient creatures in Kunark, the animals in Kunark must get tougher as well in order to survive. Why is a sabertooth in Kunark tougher than one in Steppes? Ask Darwin!
In all seriousness, we do put new creatures in the expansion (Obviously, every creature isn't a creature reused from an old zone). However we do work within certain borders, we can't get an unlimited amount of creatures. A new cat creature would mean one less Burynai (or something of the sort), so we have to balance which creatures are made during each cycle and which aren't.
While it would be nice for every single creature in an expansion to be a new one, to do that you either need to fight the same creature over and over (Fens of Nathsar filled with Burynai, Cockatrice, and Fishmen), or we reuse some older creatures to fill out some of the population. While I'm sure some people would argue whether we make the right choices when we select creatures, it is still a decision that needs to be made.
LINK
(Lyndro-EQ2) Re:Mob design
