Question

Organisms that get their energy by eating other organisms are called _______.

Answer 1

Consumers as they consume generally producers

Answer 2

Consumers. 
Producers make the energy themselves (like plants) - if I remember correctly.
Prey are the hunted organisms. 
Predators are like hunters who eat other organisms but the correct terminology used in food chains is usually consumers - primary and secondary etc. (again if I remember correctly).