A living thing that obtains energy from other things is called a heterotroph.

Here's why:

* Heterotrophs are organisms that cannot produce their own food. They rely on consuming other organisms (plants, animals, or even bacteria) to obtain the energy and nutrients they need to survive.

* Autotrophs, on the other hand, are organisms like plants that can produce their own food through photosynthesis.

Some examples of heterotrophs include:

* Animals: Lions, bears, fish, insects, etc.

* Fungi: Mushrooms, molds, yeasts, etc.

* Bacteria: Many bacteria break down organic matter to get their energy.

Let me know if you'd like to learn more about heterotrophs or autotrophs!