Multiattack. The mummy can use its Dreadful Glare and makes two attacks: one with its rotting bite and one with its rotting tail.

Rotting Bite. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 29 (4d10 + 7) piercing damage plus 27 (5d10) necrotic damage, and the target is grappled (escape DC 19). Until this grapple ends, the target is restrained, and the crocodile can't bite another target. If the target is a creature it must succeed on a DC 17 Constitution saving throw or be cursed with mummy rot. The cursed target can't regain hit points, and its hit point maximum decreases by 27 (5d10) for every 24 hours that elapse. If the curse reduces the target's hit points to 0, the target dies, and its body turns to dust. The curse lasts until removed by the remove curse spell or other magic.

Rotting Tail. Melee Weapon Attack: +11 to hit, reach 10 ft., one target not grappled by the mummy. Hit: 20 (3d8 + 7) piercing damage plus 18 (4d8) necrotic damage. If the target is a creature it must succeed on a DC 19 Strength saving throw or be knocked prone. In addition, the creature must succeed on a DC 17 Constitution saving throw or be cursed with mummy rot. The cursed target can't regain hit points, and its hit point maximum decreases by 18 (4d8) for every 24 hours that elapse. If the curse reduces the target's hit points to 0, the target dies, and its body turns to dust. The curse lasts until removed by the remove curse spell or other magic.

Dreadful Glare. The mummy targets one creature it can see within 60 feet of it. If the target can see the mummy, it must succeed on a DC 9 Wisdom saving throw against this magic or become frightened until the end of the mummy's next turn. If the target fails the saving throw by 5 or more, it is also paralyzed for the same duration. A target that succeeds on the saving throw is immune to the Dreadful Glare of all mummies (but not mummy lords) for the next 24 hours.