The Licensing Act of 1872 stipulates that operating a cow, horse or steam engine while intoxicated carries either a prison sentence or a fine. It allegedly carries a penalty fine of up to 1,200 GBP excluding the costs of looking after the cow, horse, etc. So when you go out cow-tipping, just make sure not to hop on one!
Any person found breaking a boiled egg at the sharp end will be sentenced to 24 hours in the village stocks (enacted by Edward VI). This is another law that was likely still on the books until a massive “cleanup” of archaic laws in 2012.
If a postage stamp shows the head of the queen, which they all do, it is considered treason.