Hm. Maybe it is just me being picky, but I would change the cloud to be 10ft high. It seems just more believeable and a bit more rounded that way.
Also, aren't the hide bonuses for such things usually +4 for animals, then +8 in their favorable environment?
Either that or +0/+4?

Like I said, I'm just picky, but those are the things that I might change. Otherwise, good job, as normal.