A Moodle is a disembodied gremlin with arms but no legs. It never smiles and is often crying, possibly due to failing all online quizzes. It's face is always always serious and sad. Although he constantly cries, there are no tears. His face looks something like this: ಠ_ಠ . He walks around by using his arms to manipulate stilts with webbed flippers on the end of them.
The moodle is not capable of coherent speech. Instead, it mumbles to itself, using words like VSEPR, NU, Lambda and other incoherent terms to express its' thoughts and feelings. That is, if it had any. The Moodle's mind has gone to mush after recent chemistry and physics test. He is usually confused, seen wandering the 7A wing.
Guy 1: Hey dude what the hell was that
Guy 2: That's a moodle
Guy 1: It must have gone insane after the last test.