Xanka
Small Construct, unaligned
Armor Class 15 (natural armor)
Hit Points 18 (4d6+4)
Speed walk +25, climb +15
Challenge 1/4
Condition Immunities charmed, exhaustion, frightened,
Senses blindsight 120 ft., passive Perception 10
Languages Understands the languages of its creator but can't
Special Abilities
Ingest Weapons. When the xanka is hit by a melee weapon and the final, adjusted attack roll is 19 or less, the weapon gains a permanent -1 penalty to damage rolls, after inflicting damage for this attack. If the penalty reaches -5, the weapon is destroyed. Even magic weapons are subject to this effect.
Magic Weapons. The xanka's weapon attacks are magical.
Constructed Nature. A xanka doesn't require air, food, drink, or sleep.
Actions
Absorb. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 2) force damage, and the xanka regains hit points equal to the damage caused by its attack. In addition, a living creature hit by this attack must make a successful DC 12 Dexterity saving throw or suffer a gaping wound that causes 2 (1d4) necrotic damage at the end of each of the creature's turns until the wound is treated with magical healing or with a successful DC 10 Intelligence (Medicine) check. If a creature who fails this saving throw is wearing armor or using a shield, the creature can choose to prevent the necrotic damage by permanently reducing the AC of its armor or shield by 1 instead.
Source: Tome of Beasts · OGL/Open