Hogswatch

'New paints! These are marvellous – and I have your present right here. Happy Hogswatch.'
'Thank you, Leonard.'
'Aren't you going to open it? I had assumed it was traditional.'
'Er... does it have any blades?'
'No, of course not.'
'Missiles?'
'No.'
'Is it at all mechanical?'
'Only to the extent that it utilises a small length of wire.'
'That slices things?'
'No! It just attaches the present to the box in a rather ingenious manner. Now, are you going to open it?'

As Vetinari gingerly unfastened the box, a toy clown shot out at high speed and knocked him out.