Rick and Morty's protagonist, Richard Daniel "Rick" Sanchez (Justin Roiland) is apparently as invincible because he is a genius scientist. He can do practically anything due to his intelligence, which prompts some to wonder if there's anyone who can defeat him. A number of fans are convinced that the biggest threat to Rick is Rick himself, because of his self-destructive habits and reckless behavior. Others feel his weakness is his partner-in-crime and grandson Morty. In several episodes, Rick obviously cares for him and even saves his life, suggesting Morty can be his kryptonite. However, this may be unknown to some viewers, but there's a particular character designed to bring dread to Rick. This is neither himself nor Morty, but Mr. Nimbus.