Research on @concoctionboy
A potion slime. Comprised of a viscous liquid. Usually in human form.
Created by an evil wizard, may or may not have been accidental.
Can control viscosity (how solid or liquid he is) of his slime, and can become different shapes. If he becomes too solid, he becomes permanently solidified in the shape he was in. Can split into multiple parts, and control them individually. Often solidifies them to create objects he can use.
As he is a potion, he can be drunk, but he doesn't like being drunk, and there is a limited volume of him. He can replenish lost volume over time. When consumed, the effect is seemingly random, from hazardous to beneficial.