Medium aberration, neutral evil
Armor Class: 13
Hit Points: 45 (7d8+14)
Condition Immunities: blinded, charmed, frightened
Senses: blindsight 60ft, passive Perception 11
Languages: Common, Deep Speech, Undercommon
Challenge Rating: 3
The Descender Spawn can use its action to polymorph into a Small or Medium humanoid, or back into its true form. Other than its size and speed, 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.
The Descender Spawn makes two melee attacks.
Melee Weapon Attack: +4 to hit, reach 10 ft., one target. Hit 7 (1d10+2) piercing damage.
The Descender Spawn targets another Descender Spawn within 20 feet of it that has half of its hit points remaining or less. The target spawn is destroyed and the Descender Spawn gains temporary hit points equal to the targets remaining hit points. Until the Descender Spawn loses these temporary hit points, the first Parasite Glaive attack it makes each round is made at advantage.