Teeth Possession

You imbue the thing with teeth with a boost from the weave, granting it the following effect.
Parting Gift.
When the thing with teeth causes a target to take damage, the target has to make a charisma saving throw equal to the spellcasters DC as the targets wounds grow teeth and start to attack them. If the target fails and is above half health, they are restrained, if they are below health, they are paralyzed. 

The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.