Isarra's code was the gordian knot to end all gordian knots. It's a gordian knot crossed with a gorgon's head. It turns all men to stone who gaze upon it.
Madness string 2922
Some monkeys have a bone in their penis. Humans do not, as far as I know; haven't checked them all. So yes, a skeleton can get a boner, but only if it is a non-human skeleton.