Professor Flask has a large beaker filled with green liquid on his head. He has a dark blue head and a light blue face. He also wears a lab coat and a light blue shirt and pink tie underneath. He always appears to be carrying two test tubes, one containing a pink substance and the other blue. In the anime, it's revealed that he actually has thin arms under his lab coat, and his hands are just hidden behind the test tubes, hence why they are usually not seen.