Last session I used 2 flesh golems re-skinned as "monsters made in the likeness of Ammuit, Eater of the Dead", some custom NPCs, and I converted/adapted an iron mummy (CR 4) from Gary Gygax's Necropolis...
Iron Mummy
Medium construct, any alignment
Armor Class 18 (natural armor)
Hit Points 60 (8d8+24)
Speed 30 ft.
STR DEX CON INT WIS CHA
19 (+4) 10 (+0) 16 (+3) 3 (-4) 10 (+0) 10 (+0)
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks that aren’t adamantine
Damage Immunities poison, psychic
Condition Immunities blinded, charmed, deafened, frightened, paralyzed, petrified, poisoned, stunned
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 10
Languages understands the languages of its creator but can’t speak
Challenge 4 (1,100 XP)
Alchemical Susceptibility. When struck by acid, alchemist’s fire, or similar alchemic reagants, the iron mummy is slowed for one minute. Its speed is halved, it takes a -2 penalty to AC and Dexterity saving throws, it can’t use reaction, and it can’t make more than one attack during its turn.
Eerie Resemblance. The iron mummy resembles a mummy. Each creature that can see the iron mummy can discern its true nature with a successful DC 15 Intelligence (Investigation) check.
Magic Resistance. The iron mummy has advantage on saving throws against spells and other magical effects.
Actions
Multiattack. The iron mummy makes two attacks: one lotus asp and one slam attack.
Lotus Asp. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 1 piercing damage, and the target must succeed a DC 15 Constitution saving throw, taking 10 (3d6) poison damage on a failed save, or half as much on a successful save.
Slam Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8+4) bludgeoning damage.