Shapechanger. An adult Speech Leech can use its action to polymorph into the host's tongue or back into its true, amorphous form (A juvenile can shift into food only). Its statistics are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies. It can only speak to its host when in its amorphous form.

False Appearance (Tongue or Food Form Only). While the Speech Leech remains motionless, it is indistinguishable from ordinary food as a juvenile or a tongue as an adult.

Speech Specialist. The Speech Leech has advantage on Intelligence rolls to recall information regarding a specific language or culture (History, Religion).

Ventriloquism (1/day). The Speech Leech asserts its control over its host. The victim must make a DC15 Wisdom save or be charmed by the Leech for 10 minutes. While charmed in this way, the Speech Leech can alter the voice and language of its host seamlessly giving its host the ability to speak and understand any spoken language for the duration. The host also has advantage on Charisma (Deception, Persuasion, Intimidation) checks when speaking a language the host knows.

When using this trait, the Speech Leech can directly control the actions of its host much like a Dominate Person spell, if the Leech so desires. Otherwise, the host controls its own movement and speech.

Conversion. If the target is humanoid and consumes a juvenile Speech Leech, it must succeed a DC 15 Constitution save. On a failure, the Speech Leech consumes the host's tongue and replaces it permanently.

As an action, the host can command the Speech Leech to attack once in the following ways.

Pseudopod. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) bludgeoning damage.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 5 (1d4 + 3) piercing damage plus 2 (1d4) acid damage.