During its first turn, the assassin has advantage on attack rolls against any creature that hasn’t taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.

When the assassin is destroyed, its core explodes, projecting superheated steam and shrapnel. Each creature within 5 feet of the construct must make a DC 13 Dexterity saving throw, taking 10 (3d6) fire damage on a failed save, or half as much damage on a successful one.

The assassin is immune to any spell or effect, other than its disassembly trait, that would alter its form.

The assassin has advantage on saving throws against spells and other magical effects.

If the assassin takes psychic damage, it has disadvantage on attack rolls, saving throws, and ability checks until the end of its next turn.

The assassin deals an extra 10 (3d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the assassin that isn’t incapacitated and the assassin doesn’t have disadvantage on the attack roll.

The assassin’s long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.