P44 pi-heptomino hassler is a period-44 oscillator discovered by David Buckingham on April 2, 1992. It was improved to another form by Noam Elkies in April 1996 and to the current form by iNoMed based on a reaction by cvojan on May 10, 2022. The oscillator consists of two pi-heptominos being hassled by two of a transparent catalyst (originally two heavyweight emulators) and four blocks.
Buckingham used two copies of this oscillator to make the first period-44 glider gun. This became obsolete in October 1996 when Buckingham found a gun that only used one copy of the oscillator.
In 1994 Dean Hickerson found a way to double the oscillator's period by adding two molds, creating the first gliderless period 88 oscillator. David Buckingham also found a way to triple the period before August 1994. Doubling the period with molds also works with the related p50 pi-heptomino hassler, but tripling in the same way 44 becomes 132 does not.