Actually, I think that the genies are some of the more visible of the elemental-type creatures (I guess that they are not "pure" elementals perhaps, maybe made of a number of materials).
But anyway, I thought I remembered the Manual of the Planes saying something about air animentals being for the most part invisible, while other planes (such as fire or earth) just have poor visibility because they are that way (can't really see much when stuck in a pile of earth, for example).
Re: whales - a water whale would be kind of cool...

As for devils, I've almost done all of them already!

As for the Sivak - as rather large creatures, they're somewhat tough, but if you guys ever start a Dragonlance mod, I'd be happy to try my luck. (Plus, I've already got a bit of a list of stuff to do first (including the meazel I promised SilentThief

Some stuff is redundant, but I've already some half-icons sitting around that want to be colored as well...).
But glad you guys like the icons, makes me happy

Time is becoming an ever-more precious commodity, though, I hope I can continue to churn out stuff (and someday make a mod, too!)...