Everyone. Everytime you take a step you are probably killing single celled animals.
This is a very general question so this is the general answer.
kills them kills them
almost every company that produces meat. Rarely will you find a company that kills the animals sanely.
Aquatic animals
Lots of things!
Lions and Leopards :)
It kills animals
it kills them.
logging kills trees which kills organisms such as animals
in animals it in purposely kills them in big numbers
Elephantes and other aggresive animals
A weasel is a thin, furry animal that kills and eats other animals, especially mice.
It will kills a lot of marine animals.