Vellso

Keen Smell. The vellso has advantage on Wisdom (Perception) checks that rely on smell.

Magic Resistance. The vellso has advantage on saving throws against spells and other magical effects.

Magic Weapons. The vellso's weapon attacks are magical.

Spider Climb. The vellso can climb surfaces, including upside down on ceilings, without needing to make an ability check.

Multiattack. The vellso makes two attacks: one with its bite and one with its claws.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) piercing damage and the target must succeed on a DC 15 Constitution saving throw or take 13 (3d8) necrotic damage and contract the carrion curse disease (see sidebar).

Claws. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage. Constitution saving throw or gain one level of exhaustion. If an infected creature succeeds on the saving throw, it no longer gains exhaustion levels each day. A second successful save at the end of a long rest cures the disease. The abyssal disease resists many efforts at treatment and can only be cured by a greater restoration spell or similar magic. A living creature that dies from the effects of carrion curse has a 75% chance of rising again as a blood zombie (see page 393) within 24 hours.