Furry Companions

Everyone loves pets. Anyone who doesn't hasn't really experienced the true joy that comes with having a miniature animal who loves you to death and follows you everywhere. Its exhausting, and it can be annoying, but it's arguably one of the best experiences out there - and it's no different in the sky.
However, while those on the ground have an affinity for dogs, people in the sky tend to have two varieties of pets: birds and cats. Both are more agile and more suited for life in the clouds. And while birds are wildly popular, cats are a slightly more subtle option for an animal companion, and with a little more mystique to them as well. 
Of course, it's impossible not to mention their surprising dexterity and agility as well - cats function equally well on dragonback and on the ground, and it's for this reason why they get along so well with dragon and human companions alike. Funnily enough, the first charter expedition brought a cat along with them, as cats in general are thought to bring good luck.
Aside from luck, the felines bring a number of other favorable phenomenons - occurances that range from good health to clean cupboards to muffins. And while there's a huge market for different breeds of birds, cat companions, useful and wonderful as they are, are almost always earned. 

"She showed up one day, and of course I fed her dinner. Who wouldn't? Long story short, she ended up saving me a lot of trouble - who knew cats were such excellent swimmers?"

-citizen

It might start out seeing the cat out of the corner of your eye. Like chatter squirrels, Skydweller felines are adept at caring for themselves, but unlike the michevious rodents, they almost always operate from the shadows, and their presence or the effects of their presence are rarely noticed. In fact, spotting a cat is usually seen as good luck - especially black cats, who are often said to bring good fortune. No one really knows why, but scholars suspect this is from the black cat in the children's tale of The Briar Thicket, who aided the main characters in finding their way out of a gray hollow. 
Either way, cats, while not exactly excellent judges of characters, are excellent judges of those who will give them food. They're sharp in both mind and claw, so training is possible but not always advised. But regardless of whether you can train them, cats are fiercely loyal, and you never know when they may help you out of a tight situation.

And a covering of cats wouldn't be complete without a mention of the most treasured cat of all - Old Tobbs, the feline who graces the markets of the whistlewing node with his presence, keeping away the rodents, accepted head pats, and being so popular that a song was written about him. 
And no, you're not getting the lyrics now - I'm a horrible singer!