Iceshard Whip

Weapon (whip), very rare

When you hit with an attack roll using this magic whip, the target takes an extra 1d6 cold damage and has disadvantage on the next weapon attack roll it makes before the end of its next turn.

Icy Restraints. When you roll a 20 on your attack roll using this weapon, the target also becomes restrained (escape DC 15) in a block of ice for 1 minute. While restrained this way, the target takes 1d6 cold damage at the start of each of its turns.