Hey lug, I edited the thing with the ducks in an attempt to make it more serious. I actually think they could be a thing now. Here is another idea, I'll just post more as they pop into my head:

[hider= Pugaroocusus] Pugaroocusus (singular: Pugaroocus) are small six legged insects that are about the size of a human hand. They have beady red eyes, a black exoskeleton, and large, basketball sized sacs on their backs. These sacks are typically filled with either water, water vapor, or liquid/ gaseous raw magic and are too thick to be broken unintentionally, but weak enough to be pierced or burst open by a knife or strong blow. It is nearly impossible to tell what is within the sacs before the contents are released because they are opaque. Magicians attempted to breed different Pugaroocusus, but were not very unsuccessful. The contents of the mother and fathers sacs had no affect on the contents of the child's sac (Igunus sac father + Lux filled mother= Water vapor filled child). In addition, although a Pugaroocus does not die upon having it's sac removed, the sacs seem to be an essential source of nutrients. Without the sacs, the Pugaroocusus can survive, but must eat exorbitantly large amount of food to do so. 
So why not farm Pugaroocusus? Just have a magician farm Pugaroocusus and get raw magic from them all the time? It is not that simple. Pugaroocus live in dark caves and deserts and are typically fearful of most humans. A magician would have to go out of his way to find them. They also only thrive in dark places, or places near plenty of mana pools. They don't reproduce very quickly and a mother can only give birth to a child every two years. In addition, if they are threatened, they sometimes bite, scratch, or cry out for help.
Finally, the majority of sacs contain a gallon of liquid mana at best, which isn't really too much. In short, using Pugaroocusus as a source of mana is impractical for nearly any magician. Some magicians will keep one around as a pet or good luck charm to pop open in a pinch. They can live to be over 250 years old in captivity.  
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