Death Erection or Angel Lust, Rigor Erectus or Terminal Erection, is an erection observed in a corpse upon execution by hanging.
The pressure on the cerebellum created by the noose, causes not only an erection, but also a discharge of mucous, urine and prostate fluids.
In vulva-bearers however, the labia and clitoris become engorged, alongside the discharge of blood from the vagina.
The Viktor Wynd Museum of Curiosities, Fine Art & Natural History in Hackney, London houses the longest standing boner, that of an 18th Century executed Englishman.