The serpentine rapier was a very rare prize on Treasure Hunter. It is a tiered weapon, with level requirements of 1, 20, 40, 60, and 70 Attack. During the weekend of its introduction (24 through 27 January inclusive), there was an increased chance to obtain it. It can also be obtained as a rare award from any shiny clover necklace variant. This weapon is obtained along with the off-hand serpentine rapier. Right-click it to gain the off-hand variant.