104P9 (or p9 heavyweight emulator) is a period-9 oscillator and high-clearance sparker. It was found by wwei23 on November 15, 2020 by combining 50P9 with a partial result found using JavaLifeSearch.

On December 10, praosylen and David Raucci used this oscillator to construct a p18 R-pentomino shuttle. Raucci then used it in a p63 skewed pulsar hassler on July 19, 2021, and a smaller period-54 glider gun on September 16, 2021.