On all public transportation in the UK, except for those who are exempt for various reasons, wearing a face mask is mandatory.
Understandably, what constitutes a face covering has generally been left to the discretion of the wearer.
However, British transportation officials have had to draw the line somewhere. Namely, commuters should not use live snakes as face coverings.
CNN reports a bus passenger was seen making his way to Manchester, England on Monday, with a live snake wrapped around his head and mouth.
A witness says she initially believed the snake was 'a really funky mask.' That is, until it started slithering around the handrails.