The cow topic this week was cloud dweller. Here's my take on the concept.
A descendant of the long-extinct bison that feeds upon the lilipad-like hydrop plant. The buffafloat, bobbing along since birth, has adapted to store the hydrogen from the hydrop plants in gas bladders under it's hide. Although it can use it's modified split-hoof fins to do some minor navigation, the buffafloat is a gentle creature, and it drifts along with the hydrop pastures. It's adapted a beard particuarly suited to the entanglement of hydrops. It feeds off the trapped plants in it's beard throughout the day.
Thanks for looking!
p.s. voting has started. be sure to check out http://www.conceptart.org/forums/showthread.php?t=44302 There's a lot of great stuff (as always!).