A simple yet effective stag party prank. The hair dye prank is a great option if you want to give him a shock without ending any friendships. We recommend dying his beard!
Make the stag work for his drinks on his stag night out with the busker prank. A classic choice that's plenty embarrassing but no one'll get in trouble for this one...
If you're looking for a slightly more tame stag party prank that'll give the groom a shock but won't lead to any arrests, then the broken leg prank is for your lads.
The mini stag prank is a particularly "out there" prank choice but, if you're game and your goal is embarrassment, then this one will definitely hit the mark (and be remembered forever).