Puppet Master (pictured), Puppet Master 2 (mentioned), Axis Termination (mentioned)
According to Egyptian mythology, Osiris's brother Set better known as Sutekh, along with the Queen of Ethiopia, conspired with 72 accomplices to plot the assassination of Osiris. Sutekh fooled Osiris into getting into a box, which Sutekh then shut, sealed with lead, and threw into the Nile.
Isis, the wife of Osiris searched the river and found the body of her beloved husband. She used a spell learned from her father and brought him back to life so he could impregnate her. Afterwards he died again and she hid his body in the desert. Months later, she gave birth to Horus. While she raised Horus, Sutekh was hunting one night and came across the body of Osiris. Enraged, he tore the body into fourteen pieces and scattered them throughout the land. Isis gathered up all the parts of the body and bandaged them together for a proper burial. The gods were impressed by the devotion of Isis and resurrected Osiris as the god of the underworld.
In Puppet Master 2, Andre Toulon claims that Osiris is the owner of the secret but in Puppet Master 4 he claims it was stolen from Sutekh. It is possible Sutekh murdered Osiris to steal the secret which he wanted to use for evil. Andre Toulon also owns the magical scroll with pictures of Osiris in it that he hides in the puppet's trunk. It is confirmed in Puppet Master: Axis Termination by both Doktor Gerde Ernst and Dr. Ivan that the scroll does indeed belong to Osiris.