Answer:
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
My first is a body of water. My second is me. My third came before. My fourth before all three. My fifth sounds like my first. My sixth is in a lake. Put all six together to make an animal that will keep you awake.
You are having a bad day if 12 peers deem you to be this
What surrounds the world, yet dwells within a thimble?
I open wide and tight I shut, Sharp am I and paper-cut fingers too, so do take care, I'm good and bad, so best beware.
This monkey food makes people slip and fall in cartoons.