I totally agree with Turkishmiss here, this must be a battery operated toy duck
Whilst the word "canard" does actually exist in english, the different definitions to be found in my Chamber's 20thC English Dictionary do not seem adapted to the manipulation described in the french original. In english a canard can be a false rumour (like a "canular" in french) or it can be an "early, duck-like type or aeroplane. Neither of these two definitions go with the idea of "unscrew(ing) a battery cover"
So I totally agree that the term canard has to be translated by the word "duck".
I thought this might bring on a bit of discussion. So, I would hate to reject this just because of the debate, let me know the best way to edit it so that it passes.