Dr. Acid

Origin
The character on the cover of Rucker Publications Weekender vol. 2 #1 appeared to be a mad scientist who could either make people shrink and then destroy them with an acid-like substance or was either a giant who would capture people and then destroy them with an acid-like substance. Due to the lack of regular human-sized glass beakers, however, I'm going to go with the former.

Golden Age Appearances

 * Weekender vol. 2 #1