Servitor imps are small ugly creatures of the demonic realms, ranging in size between one and twelve inches tall. Not actually evil or malign in any way, however they are almost universally rude, bad tempered and generally obnoxious.
Like all demonic entities they are extremely tough, but they lack the immunities to mundane weapons of their more powerful brethren. They are also incredibly strong for their size, the largest of them being quite capable of carrying a fully-grown man.
Although clearly sentient they are not particularly bright (lowest intelligence range for a sentient species) and, somewhat unusually for demonic creatures, have no magical talent whatsoever.
The exact origins of servitor imps is not at all clear, however most magi agree that they are not demons in the true sense.
There are several theories as to what they are: ranging from a demonic slave race to fallen angels, or even the primary intelligence in an alternate universe.
By far the most widely accepted theory, based largely on the fact that true demons refer to them as TichAbashKaraAll (lit. little punch bag), is that they are an artificial construct from the demonic realms designed as practice targets for young demons.
Summoning and Binding
Servitor imps are by far the safest (if you can ever use that term with demons) and easiest of demonic entities to summon and bind. The spells required are relatively simple to learn so even a novice mage can cast them with very little risk of failure. The imps themselves, although physically tough, have no magical abilities and are thus easy enough to control.
For this reason they are often bound to perform a variety of menial tasks (hence the name) and they are a common enough sight wherever magic is accepted. Also they are commonly summoned by trainee wizards as a kind practice exercise.