Adventures into Terror #44 [2]

A scientist invents a formula for eternal life. While he goes into town to find some rats and guinea pigs to test the formula on, his assistant back at the lab tests it on his wife and kids causing them to mutate into monsters. The assistant is horribly scarred by the mutated wife of the scientist and flees. When the scientist gets back to his lab and sees what has happened, he destroys the formula and keeps his now mutated family locked in a room in his mansion.