Dr. Gerald Deemer, played by Leo G. Carroll, is a character in the film Tarantula.
Dr. Deemer attempts to create an artificial super-nutrient which, once perfected, could provide an unlimited food supply for humanity. However, the formula is far from perfect, and it has terrible side-effects for humans and animals.
For humans, it causes a rapid form of acromegaly, resulting in death within a few days. In animals, it causes rapid and uncontrollable growth.
Dr. Deemer is very secretive and attempts to hide his experiments until he, himself, begins showing signs of the radiation poisoning side-effects. As Dr. Deemer is on his deathbed, he discloses all he knows about the formula and its effects on animals and people. But before long, the tarantula that mutated due to his formula, destroys his house, causing the debris to fall and crush the doctor to death.