Mortropagous, the spreading death. In the picture, the whip-like tail is the flagella, used for propulsion. The hairy things on the sides are cilia, used for feeding and propulsion. The bright pink center is DNA. The green rods are ribosomes.
Hope this wins! DISCLAIMER: This is a fictitious disease. It is not real, and never will be created. It is designed to be scary. This might be too scary for younger children. It's not Scratch inappropriate, though.