How do I make 8 to 16 Red LED lights (that are powered by a battery) chase in a circular pattern?

I want to "tart up" my sons Haloween Transfomer Bumblebee costume. I am going to add some simple blue LED arrays (which I have figured out) but I want to add a circle of red LEDs to the barrel of the gun - the thing I can't figure out is how to make them chase in a cool pattern...?