p55 pre-pulsar hassler is a period-55 oscillator discovered by David Buckingham on January 26, 1986, being the first period-55 oscillator to be found.
It works by hassling a pre-pulsar with various still-lifes. The original pattern is hassled by two eater 1s, four eater 3s, and two 14-cell still lifes, each composed of an eater 1 and a bun. A reduced set of still-lifes were discovered by Matthias Merzenich in June, 2011. The new version is hassled by four eater 1s, two eater 3s, and two BTSs.
4 of the originally found pattern reveals that the object being hassled is a pre-pulsar.
- 174P55.1 at Heinrich Koenig's Game of Life Object Catalogs