This was created simply by perturbing
the sides of a B-heptomino with two
LWSS's. A B-heptomino is a naturally
occurring object that lurches forward at
the speed c/2 before its own debris
usually destroys it. Not here! The
LWSS keep it alive. See BHEPTO, RAKE,
RAKE2. For a super dirty puffer, see
LINEPUF.