I like ancient Egypt, they have a cool mythology, the creatures are all odd, and the movie The Mummy (1999) has to be one of my favorites - probably because of Brendan Fraser and John Hannah. The Monster Manual already has a few interesting ancient-Egyptian-themed monsters, like the Sphinx and the mummy, but there could always be more! A party of adventurers doesn't just want to fight a bunch of scorpion people, so here are a few more monsters they might face out in those desert dunes.
In case there is any confusion, all of the Egyptian deities, like Anubis, Set, Bes, and others are treated as ancient pharaohs who may be seen as gods. This was to make it easier for the lore to be dropped into any world so that you don't have conflicting pantheons.
Ammit (CR 17) Ammit was known as the devourer of the dead and was a demon/goddess who was in charge of devouring souls or watching the souls get devoured in hell. Thought about making her into a powerful demon goddess, but went with her being a species in the Nine Hells who rumble across the landscape in search of souls to devour in their crocodile mouths.
Beset (CR 4) Bes was the protector of households, and his feminine counterpart, Beset, helped him guard his people. Now, beset is the name of a house spirit, an elemental that has been bound to a home to protect it from outsiders and maintains the house and ensure it is in good condition.
Jackal Warrior (CR 5) I like The Mummy, and the jackal warriors in The Mummy Returns was pretty awesome. The Army of Anubis is made up of a mysterious group of jackal-headed warriors, and no one is quite sure where the pharaoh Anubis found them! While they were once a massive army that stormed across the desert, their members have decreased so only a few hundred marauders are left alive while they continue to follow the last orders given to them by Anubis.
Serpopard (CR 3) This is a strange monster from Egypt with little information on them. They are presented as leopards with long necks, often compared to serpents. Their name actually comes from the combination of serpent and leopard since they were never given true names that we have been able to find out. They are vicious hunters who use their exceptionally long necks to peek over sand dunes as they search for prey.
Sha (CR 8) Also known as the Set Animal, it is said that Set created them to be great and clever hunters, granting them supernatural powers. Or that they are Set given animal form. Regardless, they have a strange head, like that of an anteater or a horse, with a forked tail, and black or red fur covering their canine forms. They have the power to control the weather and can attack with the power of the storms.
Criosphinx (CR 7) There are more sphinxes/sphinges (apparently both are correct), than just the androsphinx and the gynosphinx. The criosphinx is one of them, though they are seen more like beasts than proper sphinxes by the more powerful of the spinxes. They lack spellcasting, but make up for it by being powerful predator. They have a ram's head and horns on the body of a winged lion.