Basilisk venom

Basilisk venom is an extremely poisonous and corrosive substance generated by said species.

Overview
Basilisk venom is extremely powerful, and can kill a person within a little more than a minute at best, making the person drowsy and blurry-visioned before they die. The strength of the venom is one of the few substances known to be capable of destroying Horcruxes, causing them fatal damage that cannot be repaired. It only has one known cure: phoenix tears, which happens to be very rare, increasing the venom's deadliness.

The venom's potency is apparently extremely long-lasting, as Hermione Granger was able to use the venom from the fang of a Basilisk that was dead for nearly five years.

Basilisk venom is one of the few poisons that are not curable by Bezoars.

1993
In 1993, Harry Potter stabbed the roof of the basilisk's mouth with Godric Gryffindor's Sword, and ended up getting a fang splintered into his arm. Tom Riddle described the venom should kill Harry within a little than a minute to live, though Fawkes's tears healed Harry's arm and cleansed the poison.

After being healed, Harry took the fang and stabbed Riddle's diary, destroying that Horcrux beyond magical repair. Because Harry had stabbed the Basilisk with the sword, it was imbued with Basilisk venom, and was therefore able to destroy Horcruxes as well.

1996
Albus Dumbledore used Gryffindor's Sword, which has been imbued with the basilisk's venom three years prior, to destroy Marvolo Gaunt's Ring.

1997
Ron Weasley used Gryffindor's Sword to destroy Salazar Slytherin's locket.

1998
In 1998, during the Battle of Hogwarts, Ron and Hermione went down to the Chamber of Secrets and destroyed Helga Hufflepuff's Cup with a basilisk fang. Neville Longbottom used Gryffindor's Sword to kill Nagini.

Appearances

 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Chamber of Secrets (film)
 * Harry Potter and the Chamber of Secrets (video game)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part 2
 * Harry Potter and the Deathly Hallows: Part 2 (video game)
 * LEGO Harry Potter: Building the Magical World
 * LEGO Harry Potter: Characters of the Magical World
 * Harry Potter LEGO Sets