Not sure, but maybe: "Quis crepuit crepulum." Who rattles the one/thing rattling? I want to say that adding the "s" is a medievalism, but I can't find evidence

Not sure, but maybe: "Quis crepuit crepulum." Who rattles the one/thing rattling? I want to say that adding the "s" is a medievalism, but I can't find evidence of that. Crepo is also first conjugation so this might just be totally wrong. Maybe it was just to make the phrase closer to custodiet and custodies?