Cap of Thorns

Donning this thorny wooden circlet causes it to meld with your scalp. It can be removed only upon your death or by a remove curse spell. The cap ingests some of your blood, dealing 2d4 piercing damage. After this first feeding, the thorns feed once per day for 1d4 piercing damage. Once per day, you can sacrifice 1 hit point per level you possess to cast a special entangle spell made of thorny vines. Charisma is your spellcasting ability for this effect. Restrained creatures must make a successful Charisma saving throw or be affected by a charm person spell as thorns pierce their body. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If the target fails three consecutive saves, the thorns become deeply rooted and the charmed effect is permanent until remove curse or similar magic is cast on the target.