Step 1: Basic equipment
Smallish clean rocks to mostly fill the small container and hold the pump inplace.
One small, low volume fountain pump. A larger, high volume pump may shoot the stream on to the ceiling or across the living room.
Step 2: Fountain pump
Step 3: Rocks
Step 4: Assembly
Cut the length to reach over the rocks and above the water line to what ever height is right for your application.
If the pump has little suction cups them stick it wear you want on the bottom of the smaller, rock containing container. Then surround the pump with rocks to hold it inplace.