GRIM REAPER. “The development of the Drosophila embryo into an adult fly is a process that integrates cell proliferation and differentiation with programmed cell death, or apoptosis. Apoptosis is an evolutionarily conserved process that is controlled in the developing fly by the products of the genes reaper, grim, and hid.”
http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-0177(200005)218:1%3C68::AID-DVDY6%3E3.0.CO;2-9/full