Free ship is a common period-6 photon in Live Free or Die which has a large tail spark, and can be turned into puffers. Two of them emerge from the domino sequence. There is a shorter variant of the free ship called the short free ship, but it is rarer due to not evolving from the domino.
The free ship was initially discovered by Luke Bradford, the creator of Live Free or Die, and was one of the patterns that initially interested him in the rule.[1]