In today's comments, we contemplated the migration of the butterfly, explored some unfortunate options in Halloween costumes, and learned just why the Klingons are the most easily-toppled warrior empire in the Trek-verse.
From this post on sci-fi warrior empires who have proven surprisingly conquerable, commenter dlthurston shares this tidbit:
Remember, the entire Klingon race evolved for the purpose of being easily defeated to prove the severity of a given situation. It's an odd evolutionary niche, but they've really managed to find some long term successes.
Ah, but what curious kind of environment could have triggered so unusual a set of evolutionary responses? Turns out, a writer's room:
TV Tropes calls it the Worf Effect. He's the Klingon on the left in the top picture and the middle in the last picture. He's supposed to be the toughest person on the Enterprise, so inevitably gets flung around like a rag doll whenever the writers needed an easy way of showing just how dangerous a given situation was.