Waxwork golem

False Appearance.  While the golem remains motionless, it is indistinguishable from a normal wax mannequin.

Binding Wax. Creatures have disadvantage on attempts to escape the golem’s grapple.

Melt Away. If the golem takes 5 fire damage in a single instance of damage, it instantly ends its grapple on any currently grappled creatures, and its attacks for the next round do an additional 1d6 fire damage.

Immutable Form. The golem is immune to any spell or effect that would alter its form.

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

Magic Weapons. The golem’s weapon attacks are magical.

Hardening. If the golem receives Cold damage, it will instead heal for the same amount. If, however, this would bring it above its original starting HP, it will become brittle and shatter.

Multiattack. The golem makes two slam attacks.

Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 5) [bludgeoning] damage. If the target is hit by 2 Slam Attacks, it must succeed on a DC 15 Constitution saving throw or be stuck to the Wax Golem and is considered grappled. A creature may attempt to break the grapple at the start of each turn, DC 18 Strength (athletics) check. The Golem may grapple only one creature this way at a time.