somnifecator

Well, 'to shit' in Latin was caco (-are, -avi, -atus[/i]). Feces is from fæx, fæces, 'dregs, lees' and was a Medieval euphemism for stercus, stercoris, or merda, merdæ, 'shit'. I suppose if you want you could have somnicacator ...

Ceci n'est pas un seing.