There is something so sinister about a human experiment gone awry, creating a human/monster chimera. Here's some of my movie favorites -
Swamp Thing
This 1980s cult favorite involves a scientist whose experiment is tampered with by an evil villain. When he tests it, he becomes a monster.
The Incredible Hulk
When the military uses gamma rays to transform a soldier into an invincible warrior, Bruce Banner becomes a green hulking monster when angry.
The Fly
A scientist, working on a device to transport people from one location to another, decides to try it out, only a fly enters the machine with him. When he reforms in the receiving machine, he is half man/half fly.
Frankenstein's Monster
A scientist believes he could bring life to a creature cobbled together with dead people's body parts. When he adds electricity to revive it, the monster ends up being an angry and tortured creature.
Altered States
A scientist performs experiments with psychotropic drugs combined with deprivation tanks. He has what he believes are genetic memories of primitive eras and turns into a primitive feral being.
Hollow Man
A scientist volunteers to test a serum. It renders him invisible and he cannot get back to his normal state. He becomes a dark evil and invisible monster.
Dr. Jekkyl and Mr. Hyde
A kind and gentle scientist experiments to learn about his other half - the dark half. This alter ego is unrepentent and criminal.
I'm not sure what we take away from these films except apparently scientists, like Marie Curie, are doomed to succumb to their own experiments.
Perhaps I should also do a post on radioactive monsters. Those have been fun since the 1950s!