This one starts out pretty tame with the water prank. But rest assured, the second round pen prank satisfies. We very much appreciate the 'safety' of adding water to the pen body in case the flame gets out of control. Nobody laughs at third degree burns.
NextRaker is one of our favorite class clowns. From his profile pic, it appears he models himself a modern Latino Ferris Beuller.
In the spirit of rogue studies, we hit the books on the chemistry of this prank.
Nex uses safety matches and a basic Bic pen. He scrapes the match head into the pen cap and coats the pen body with the safety matchbox strike surface. The flame ignites by way of friction between the strike surface (25% powdered glass, 50% red phosphorus, 5% neutralizer, 4% carbon black and 16% binder) and the match head (45-55% potassium chlorate, 20-40% of siliceous filler, diatomite and glue). That's a pretty involved chemical reaction.
An alternate prank could use the traditional strike-anywhere match and therefore would not necessitate the matchbook surface to be inserted into the cap. The phosphorus on the match head would simply ignite due to the friction with the plastic pen body.