Large rodents, similar to rats. Given enough time, they can even chew through stone. They'll eat almost anything, and the ore they ingest when they're growing is deposited in their bones, teeth, and fur, making them stronger. Fortunately, like most rodents, they're not particularly brave or aggressive, unless defending themselves or their nest. They will attempt to kill a lone kobold if there are enough of them. They range in size from normal rat size to over three feet long, not including tail.

Something like a large, eyeless bat. They have a huge mouth with several rows of teeth. Their primary attack is auditory, so if you plug your ears, they're not too difficult to kill in small numbers. They tend to nest in large caverns, and there may be many hundreds or thousands of them. The long, thin wing-bones are the primary source of arrow shafts for kobolds in the upper levels, but they're neither particularly sturdy nor straight. 

Beasts of burden in some parts of the mountain. Imagine a yak with bonus horns on head and nose, and about half again as large. One of the few creatures kobolds have domesticated, thanks in part to their usually passive personalities. As long as they have food and aren't in pain (their thick skin prevents accidental injury) they won't object to being asked to haul heavy weights. The trick is keeping them fed, since most kobold tribes have just enough food to support their own members. Their fur is thick and warm, and is the only source of real cloth in the mountain.

There are several different types of packs used by kobolds. They're all made of thick, sturdy leather, which helps protect the wearer's back, as well as the contents. They're fastened with a leather cord or a toggle carved from bones or teeth.

• The gatherer's pack is the largest, and used primarily by young kobolds. While it's usually carried on the back, it has longer straps than the others, so it can be swung around to the side and the top opened while gathering. It only has one buckle, tie, or strap across the front to keep it in place if the wearer needs to run. These are usually passed around among the tribe when the pup becomes an adult.
• The warrior's pack is smaller, and holds very little besides the basics:  food, water (in a cleaned bladder), cleansing moss, firemoss, zhiwu web, maybe a fire-striker or mamu moss if they're lucky. These have three or more wide straps across the chest, which serve as a simple leather armor. They aren't meant for the wearer to access, but are simple for the other warriors nearby to get into, allowing the whole group easy access to needed supplies.
• Female's pack - These are highly individual, depending on the needs and personality of the wearer. They tend to be larger than a warrior's pack and smaller than a gatherer's pack, and are usually only worn when outside the den, unlike the others. They usually have only one strap across the chest, though more may be added if the female requests them. These packs may be highly decorated, unlike the others.