Grind tongue ticklers (the candy which pops in mouth) very fine and camouflage it with sugar. The moment anyone puts them in their mouth, it starts crackling. But don't mix them in any liquid because it will start bubbling.
In drinks, replace whiskey with diluted tea water and use coke instead of rum and watch the fun, as your guests will get an entirely different taste in their cocktails.
You can also tamper with colorless drinks like gin, vodka and tequila. In place of tequila, serve a shot of water and the victim won't realize it soon because the salt and the lemon taste will stay.
You can also trick your friends visually with the drink recipe given below called Black Magic:
Ingredients:
- 150ml Pineapple juice
- 30ml dark rum
- Dash of orange squash
- Dash of lemon juice
- 10ml grenadine syrup
- 30ml Peter Herring cherry liqueur
Method:
- Blend all the ingredients with three cubes of ice
- Pour this in a cocktail glass and serve
When served it's off white in color due to the pineapple juice but as it settles down the color of dark rum appears.
But remember the pranks you are playing with your friends should be harmless. The idea is to sit back and laugh your heart out.