Malkite themfar/Legends

Malkite themfar was a lethal neurotoxin used extensively by assassins, bounty hunters, and the Malkite Poisoners. Boba Fett used darts laced with this substance on his knee pad rocket dart launchers. It worked instantaneously, and could be applied to weapons in a variety of ways. A being could even apply it to their fingernails, let the poison dry, and it would still retain its potency.

Sources

• The Essential Guide to Weapons and Technology (First mentioned)
• Pirates & Privateers (as Malkite poison)
• Boba Fett's Armor: An Essential Guide to a Walking Weapon (as Malkite Them Far)
• Arms & Equipment Guide
• The Official Star Wars Fact File 52 (KAM2, Kamino Saberdart)
•  Kamino saberdart in the Databank (content now obsolete; backup link)
• Endless Vigil