A long thin blade of serpentine design. Its blade poisons the blood of its victims (creatures without blood are unaffected.)

As an action, you can use the blade to transform into a Giant Poisonous Snake, which you control, for up to an hour at a time. You can see what the snake sees. You can distinguish this snake from others, and as an action, you can pick it up to turn it back into a sword. You can use this action once per long rest.

If you fail to transform the snake back into a blade when one hour is up, it will become a blade again wherever it is currently. The blade cannot transform again for 8 hours. If the snake dies, it becomes a Broken Viper Blade.

A Broken Viper Blade cannot transform into a snake again, and its poison damage is reduced to 1d4.

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Melee Weapon Attack: Slashing, Weapon Property: Light, Damage: Poison, Poisoned, Damage, Combat, Versatile, Sap