A microscopic elephant that shares a flat with your brain cells. Brain cells aren't actually smart. They copy schmoo's homework, therefore the more schmoo you have; the more smarts you have.
Certain species of schmoo have also been shown to make a person lucky, schiztophrenic(yes, symptoms of the poetic muse have been traced to schmoo) or even hyperactive. Scientists are currently investigating other locations where schmoo are found.
Person 1: he got an A+++++++!!! I didn't even know that was possible!
Person 2: He must have a lot of schmoo
Person 1: my schmoo speak to me
Person 2: you should get help