Quellvisks (quell='kill, crush completely' visk='move quickly') are - or rather, were, since they're all extinct by now (see below) - huge and crushingly stupid herbivorous ruminants that lived peaceably in the lush and fertile lands of Vidik Amar. The reason that the lands of Vidik Amar were in fact so lush and fertile is that quellvisks were only good at one single thing - the constant production of towering mounds of manure that served to enrich the soil so hugely.
Quellvisks are odd-looking behemoths. Typically standing near-on thirty feet tall at the shoulder and each weighing fifteen tons, they somewhat resemble gigantic cows. That is, the sort of gigantic cows that you might see if you were on a really freaky acid trip, since quellvisks have dappled green and purple hides, small black horns, orange hooves and bright blue eyes. Despite their immense size, quellvisks have a brain the size of a single M&M™ - a thing which undoubtedly explains their overweening dumbness. These creatures are so stupid that they look up to plankton as being gifted.
1. Making manure.
2. Mooing and dribbling.
3. Burping and farting.
4. Nothing else.
A love-lorn Demimage named Jerrick attempted by the use of his puny theurgies, mild skill at papier maché sculpting and numerous rolls of duct tape to transform the quellvisks into a rampaging horde of terror in order to trample Elemesnedene, the home of the haughty Elohim into utter destruction. This didn't go well, hence the reason for the quellvisks now being extinct. See the section on the Demimages of Vidik Amar for the full and tragic tale.
The quellvisks turned out to be more useful dead than alive, since Jeremiah Avery found an unusual use for their bones in helping him to practice a form of figurative self-necromancy and emerge from the graves of his mind, or, according to the opinion of the fandom, come down from a long-lasting shroom high.