Four molds hassling eight blocks is a period-52 oscillator consisting of four molds hassling four bi-blocks in the same way as the p18 bi-block hassler. It was discovered by Noam Elkies on February 21, 1995.

The variant shown in the infobox (the same variant as in Hickerson's stamp collection) shows two different ways in which the molds can be arranged. A 31-glider synthesis is known for a rotationally symmetric version of this oscillator.

This pattern is a oscillator.
The population fluctuates between 83 and 86.
This pattern is periodic with period 52.