First I think the more iconic ones should get their own BGM. I personally have mine turned off cause it's all so bleh. I think that's been requested before, maybe more so on the magitek back in the day.

Off the top of my head, Ixal wolf could howl, the Kobolds bomb thing could smoke or maybe have one do a small blow up animation. Behemoth could not disappear when you zoom in to check out how pimp you look, as well as Sleipnir... Sleipnir could also stand to have slightly longer legs. He looks like an over sized pony. Or is that just me?

One thing I think could be pretty cool though, have him able to menacing stand on his hind legs. Much like he does in those early ARR trailers.

http://youtu.be/h542YbZuwkQ - at 6:40min in.