Also, looking for the etymology of poop-noddy, it's broken down (of course) into poop: "Origin unknown. Compare earlier POOPED adj.1 Perhaps compare Dutch poep derogatory term for a German, especially a migrant worker from northern Germany (17th cent.), also ‘foreigner’ in general (1798), of uncertain origin.
trans. To fool, deceive, cheat, cozen; (also) to overcome. In quot. 1609 with punning allusion to POOP n.1 2."
And noddy: "Origin uncertain. Perhaps < NOD v. + -Y suffix6, or perhaps (in sense 1) shortened < NODDYPOLL n. Compare later NOD n.2 In sense 2a perhaps with allusion to the nodding behaviour of the birds during courtship."