Snacker is a pentadecathlon with eater 1 stabilizers that force it into a lower period (from 15 to 9). It was found by Mark Niemiec in 1972. The stabilizers make the domino spark largely inaccessible, but the snacker is extensible as shown below and so a more accessible period 9 domino spark can be obtained – this is exactly the method that was used to create the first period 18 oscillator, 117P18.
Additional pentadecathlons can be added to extend snacker. The alternate stabilization on the right was found by Dean Hickerson in April 1998.Download RLE: click here