Animated Elephant Statue

Achilles' Heel. The statue is instantly rendered inanimate if a mouse, an illusion of a mouse, or even a realistic two-dimensional picture of a mouse is displayed to the statue within the range of its blindsight.  The creature must be a mouse; other rodents have no effect on the statue.

Antimagic Susceptibility.  The statue is incapacitated while in the area of an antimagic field.  If targeted by a dispel magic, the statue must succeed on a Constitution saving throw against the caster's spell save DC or fall unconscious for 1 minute.

False Appearance.  While the statue remains motionless, it is indistinguishable from a normal elephant statue.

Trampling Charge.  If the statue moves at least 20 feet straight toward a creature and then hits it with a gore attack on the same turn, that target must succeed on a DC 12 Strength saving throw or be knocked prone.  If the target is prone, the elephant can make one stomp attack against it as a bonus action.

Gore. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 5) piercing damage. 

Stomp. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 21 (3d10 + 5) bludgeoning damage.