Almost all LEGO creations are miniature or Micro-Scale. But in general, models that are smaller than minifig-scale are Micro-Scale.
The cool thing about building in Micro-Scale is that you don't need a huge amount of LEGO to build something really interesting.
I ask that you please place a penny in your photo to show everyone the scale of your creation. Remember, this design needs to be smaller than normal LEGO arrangements.
Here is a links to some very amazing Micro-Scale sculptures to give you some inspiration. I did not link to LEGO micro-sculptures because I'd like you to come up with your own ideas.
Just think as small as you can!
Here you can see what other kids from around the world created for this response.