A small suggestion - the staple animal creature types seem to be canines, felines, and reptiles. The first two have interesting level 4 creatures, but reptiles don't. That's too bad, because reptiles with their condition markers are real interesting. Anyway, I wouldn't say no to a level 4 mid sized dinosaur or raptor pack leader (adding +1 or +2 to reptile effect rolls would be sufficiently different from previous pack leaders).