If you want to simulate the roar of an animal, an angry tiger or lion for example, take a corrugated cardboard box, place two condenser mics (one outside the box, recording overall and the second facing the surface from the inside, to catch the resonance of the space), take a pen and start drawing the surface of the box!
You’ll notice that depending on how you pressure the pen, the roar becomes more severe, more intense. Of course, you can experiment and change any of the variables mentioned it above, as for example: The size of the box, mic types and placement, writing tool (pen, pencil, marker ) e.t.c. Here’s an example.
– Kostas Loukovikas