Answer:
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
A leathery snake, with a stinging bite. I'll stay coiled up, unless I must fight.
Someone walked into a room and you heard a crash! Someone died. What happened?
I run through hills. I veer around mountains. I leap over rivers. And crawl through the forests. Step out your door to find me.
I can ruin your day, or darken your life. And while I'm expected, I'm never alright. I'm bad for business, and worse for your hair. Wherever I am, there's something not there.
Often cooked as fillet, this meat comes from an animal that swims underwater.