krtek a houby
Merry Xmas!
Definitely myth. Bought a half of it in a Camden pub in 88 or 89.I vaguely remember something about half pints of snakebite being illegal because it would mean serving a quarter pint of each drink, which wasn't allowed. Probably nonsense.
Urban myths were a way to amuse ourselves before the internet!
However, the following year they weren't keen on serving snakebites or punters drinking outside the venue.