Battleloths were created in the likeness of weapons. Choose a kind of weapon from the Weapon Types table. Your choice affects your weapon form, natural weapon, battle adaptation, and appearance.

At higher levels. While in your weapon form, you gain a magic bonus when you reach levels 5 (+1), 10 (+2), and 15 (+3).

As a living weapon, part of your anatomy resembles your weapon type, granting you a powerful natural weapon. When you take the Attack action on your turn, you can replace one of your attacks with this natural weapon, which is treated as magical for the purpose of overcoming damage resistances and immunities.

You have a special benefit or ability determined by your Weapon Type trait.

You have Darkvision with a range of 60 feet.

As a Bonus Action, you can transform into a magic weapon, treating yourself as a Tiny object. While transformed, you are treated as being Petrified, but you remain aware of your surroundings, can speak telepathically, can take actions which do not require you to move your body, can cast spells which do not have somatic or material components, and can use Shapechange to transform back at will. If your wielder hits a target with you, you can treat the hit as though you made it.

In addition, your weapon type grants you special abilities while you are being wielded, including special Reactions.

Finally, if you are wielded against your will, you can impose Disadvantage on an attack made by your wielder. If your wielder rolls a 1 to hit, you can make a natural weapon attack against them, causing them to drop you. 

Most Yugoloths are immune to acid and poison damage, as well as resistant to cold, fire, and lightning damage. As lesser Yugoloths designed to be exploited by their creators, Battleloths are only resistant to acid and poison damage.