Camouflage. While the stone atronach remains motionless, it is almost indistinguishable from an inanimate block of stone.   Grounded. The stone atronach cannot be be knocked back, be knocked prone or otherwise moved against its will. However the stone atronach is incapable of Jumping, Dodging or taking the Dash action.   Explode on Death. The stone atronach explodes in a sphere of lightning bolts upon its death, any creature within 10 feet of the stone atronach when it dies must make a Dexterity saving throw, taking 2d10 lightning damage or half as much on a successful save.