Recently I've watched Comedy Club and there a terrible secret of Soyuzmultfilm has been revealed.
To my horror I found out that poor artists had to work in poorly ventilated rooms with some very toxic paints which happend to be hallucinogens and soon they had become addicted to them.
A hedgehog in the Mist, Cheburashka and other freaks were born out of the diseased imagination of that poor fellows.
By the way, at first they've created Cheburatino, but it was too horrible a monster for innocent children minds