Marie-Jeanne and Henri conducted a druidic blood ritual to forge the pike. The steel of the weapon was forged out of wolfsbane, mountain ash and Marie-Jeanne's blood, under the light of a full moon. Once fully forged, the pike was preternaturally lethal to La Bete, due to his being Marie-Jeanne's blood relative, her own brother.
In 1767, Marie-Jeanne finally tracked down La Bete, then speared the super-powered werewolf through the chest with the pike eventually killing La Bete. The pike later came to be in the possession of Marcel, Sebastien's devoted comrade.
The pike was kept by Marcel in his guise as the Surgeon throughout the centuries, and by the series present had been reforged into a sword, disguised as a cane. In Season 5, when the Dread Doctors began their experimentation, abducting and producing the chimeras the surgeon would usually use the pike to kill off the chimeras and they died instantly.
After the Beast of Gevaudan was resurrected and the Dread Doctors were killed, the pike was identified and recovered by the Argents, and Gerard Argent confirmed the pike will definitely kill the Beast. Chris Argent passed the pike to Scott's pack whilst they work to save Mason Hewitt, who was being used as a corporeal host for Sebastien's spirit to bring the Beast back to life. In the final showdown between Sebastien and the pack, Mason's true form was separated from Sebastien's spirit, and Scott finally used the pike to vanquish Sebastien Valet once more, spearing Sebastien's spirit, killing la Bete du Gevaudan once again and the pike itself dissolved.