Mark Twain’s Fountain Pen

Origin
Mark Twain, birth name Samuel Clemens, was an author and satirist best remembered for his various witty works, including The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn. Twain first started out as a riverboat pilot and miner before becoming a celebrated journalist and author. Twain lost large amounts of money on bad investments but was later able to fully repay his creditors, even though he had no binding responsibility to do so. Twain was born with the arrival of Halley’s comet and his death coincided with its next return and departure.

Effects
Used by Twain to write The Adventures of Tom Sawyer, the user slowly develops increased imagination, wit and intellect, but will become very bitter to the human race as a whole. Also, they will die on the day of Halley's comets passing, providing they are still alive.