This magical whip is fashioned from living thorny vines that seem to have a will of their own. The thistles of the magical whip coat themselves with a thin layer of toxic sap, dealing an extra 1d4 poison damage to those struck by it. To attack with Thistlegrasp in this manner you use your wisdom modifier. You count as being proficient in Thistlegrasp when wielding them. 

When attuning to Thistlegrasp, thorny tendrils will wrap around the wielder's chosen arm, bonding to the attuning creature and reducing its max HP by one as the plant feeds on the wielder's blood. If the wielder becomes a friend to Thistlegrasp, they will be able to remove the whip freely, otherwise the wielder will take 3d6 slashing damage in the process of pulling Thistlegrasp off their arm. 

Thistlegrasp has the ability to restrain targets by rapidly extending and growing its thorny vines tightly around an enemy. The wielder may target a creature within 20ft and command Thistlegrasp to restrain them, that creature must make a DC 16 strength save or be restrained , taking 1d4 slashing damage that repeats every round it remains restrained. The restrained creature can use its action to make a DC 16 strength check to break free from Thistlegrasp every round it remains restrained. If the wielder moves further than 20ft from the restrained creature the effect immediately ends. Cannot be used as a whip while this effect is active. After using Thistlegrasp to restrain a target, it cannot be done again until the sentient plant has spent a night basking under the light of the moon.

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

Notes: As well as being a weapon Thistlegrasp is a sentient plant with wants and needs of its own. Thistlegrasp enjoys warm nights under the light of a full moon, soil watered with blood and gentle petting around the thorns. If treated well Thistlegrasp will be a loyal protector to its wielder, Finesse, Reach, Slow