Biting Cold

You empower your bite with the fridged cold of winter and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack's normal effects however, the damage type of the attack becomes cold damage and the target's speed is reduced by 10ft until the end of your next turn. 

This spell's damage increases when you reach certain levels. At 5th level, the melee attack deals an extra 1d8 cold damage to the target on a hit, and their speed is reduced by 5 additional feet. Both damage roll and speed reduction increase by 1d8 and 5ft at 11th level (2d8 and 20ft) and 17th level (3d8 and 25ft).