Just a couple critters from real life that fascinate me, and maybe could inspire some game ideas...
The most mesmirizing thing I've watched was a tank of baby cuttlefish - the skin colors change like a tv screen up close, and the skin texture changes from smooth to bumpy as well. They ink when startled too - in real life it's black and blocks your view of them, but the Giants could get really artsy with colors possibly.
Spiders - like garden spiders, that have interesting patterns and colors on them - not scary, just interesting and sometimes beautiful. I'm envisioning a street that's almost nothing but spiders - all sizes just hanging about benignly on their webs or on trees looking cool.