Tiny beast, unaligned

• Armor Class 10
• Hit Points 1
• Speed 10 ft., burrow 10 ft., climb 10 ft., swim 10 ft.

STR	DEX	CON	INT	WIS	CHA
1 (-5)	10 (+0)	1 (-5)	1 (-5)	7 (-2)	1 (-5)

• Skills Stealth +2
• Senses darkvision 30 ft., passive Perception 8
• Languages —
• Challenge 0 (10 XP)

Actions

Tongue Bite. The louse crawls into the mouth of an unconscious humanoid on a successful Dexterity (Stealth) check with advantage against the target's passive Wisdom (Perception). It then secretes a poison which numbs the mouth on a failed DC 10 Constitution save. The numbing takes 1 minute to take effect, at which point the louse begins to consume the tongue by swallowing it whole and digesting it with acid, which takes 1 hour. If anyone notices the louse before the end of this process, it can be removed with a successful contested Strength check. If the discovery was made within the first 9 minutes of consumption, the target will be unable to speak until after a long rest but will experience no ill effects beyond that. If the discovery is made 10–60 minutes after consumption, the target will permanently experience the effects of Minimal Tongue with an IE equal to the number of minutes ÷ 20 rounding up.

If the louse is removed after 10 minutes, a DC 10 Wisdom (Medicine) check will be needed to stop the bleeding, or the target will lose 1 hp per round until dead.

At the end of the hour, the louse has attached itself to the nervous system through the nerves in the mouth, and any attempt to remove it short of a Greater Restoration or Wish spell will kill the host.

Once attached, the louse responds to neural commands and acts like a tongue with a Speech Impediment (difficulty pronouncing labial sounds due to trying to hide the louse, but you must succeed on a Charisma (Performance) check against the passive perception of anyone they talk to within 10 feet to conceal it or experience disadvantage on all Charisma checks with those aware of the louse.

A tongue louse lays 10 eggs every week along with a foul-tasting liquid, prompting the host to want to spit it out. These eggs will hatch in 7 days and begin to seek hosts.

Your tongue is outside the shape typical for your ancestry. Choose or roll on the following table. While most of these have their own benefits, they are not conducive to speech, so unless otherwise noted, this gives you a −(IE) penalty on all speech-related ability checks, saving throws, and attack rolls, and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls, and when learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.

d20	Difference
1–6	Extended
7–9	Forked
10–16	Minimal
17	Prehensile
18	Proboscis
19	Symbiotic
20	Vampiric

• Extended. Your tongue is much longer than is typical for your ancestry, (IE) feet. This allows you to eat insects from a colony, like ants or termites, for which you have a preference.
• Forked. Your tongue is long, thin, and forked, giving you an improved sense of smell; you can easily detect the direction smells are coming from by flicking your tongue in and out of your mouth. This gives you advantage on Wisdom (Perception) checks involving smell, but because many people fear snakes, you have disadvantage on Charisma (Persuasion) checks. A forked tongue has no IE. You have disadvantage on all speech-related Charisma checks and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls. When learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.
• Minimal. Your tongue is smaller than expected for your ancestry or (IE 4) missing. This also gives you −(IE) on Wisdom (Perception) checks related to taste.
• Prehensile. Your tongue is attached to the front of your mouth, and you can use it to grab items up to your height away and pull them to yourself as an action. Your tongue has a Strength equal to 1/2 your Strength attribute, rounding up, and can grab items and move them toward or away from you. A prehensile tongue has no IE. You have disadvantage on all speech-related Charisma checks, and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls, and when learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.
• Proboscis. Your tongue is hollow, enabling you to drink through it like a straw. You are unable to consume solid food and have no teeth. A proboscis has no IE. You have disadvantage on all speech-related Charisma checks, and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls, and when learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.
• Symbiotic. Your tongue was eaten by a Tongue Louse, and it now functions as your tongue in a parasitic symbiosis. Symbiotic Tongue has no IE, and you have disadvantage on all speech-related Charisma checks, and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls, and when learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.

• Vampiric: Your tongue is hollow, and your teeth form a circle at the end of it like a lamprey. You prefer to drink liquids, especially blood, but can also consume soft foods. You can use your tongue to make an unarmed attack, causing 2 (1d4) piercing damage, and on a successful hit, you attach yourself to the victim. Once attached, you need not roll to hit and automatically cause 2 (1d4) damage. Vampiric tongue has no IE. You have disadvantage on all speech-related Charisma checks, and you must modify spells with verbal components to work within your verbal range, so you cannot use spell scrolls. When learning a new spell with a verbal component, it takes twice as long to copy it into your spellbook as usual.

Real-world Examples

Macroglossia, Kawasaki Disease, Fissured Tongue, Cymothoa Exigua

Assistive Options

Besides a mask to cover the mouth, you may benefit from learning a sign language, which can be exchanged for any language or proficiency.