Sand. Zotireres imposes disadvantage on all attack rolls against him when he is reduced to less than one hundred hit points. This trait cannot be activated if Zotireres has taken lightning damage.

Amorphous. Zotireres can move through a space as narrow as one inch without squeezing.

False Appearance. When Zotireres lies motionless in the sand, he is indistinguishable from normal sand. 

Constantly Changing. Zotireres is constantly changing shape. As a result his armor class changes every round. Before each of Zotireres turns, roll to see his armor class. (17+1d4)

Innate Spellcasting. Zotireres spellcasting ability is Charisma. (spell save DC 16, +6 to hit with spell attacks.) Zotireres can innately cast the following spells, requiring no material components.:  

3/day: Maximilian's Earthen Grasp                                                                                              2/day: Wall of Sand, Erupting Earth                                                                                                1/day: Bigby's Hand,  Conjure Elemental (Earth Only)                                                                                           

Multiattack. Zotireres makes three arm attacks then either suffocate or wave of sand.

Arm. Melee Weapon Attack: +10 to hit, reach 20 ft., one target. Hit: 20 (4d6 + 6) bludgeoning damage. 

Suffocate. Melee Weapon Attack: +10 to hit, reach 100 ft., one target. Hit: 40 (10d6+10) bludgeoning damage and the target must make a DC 20 Constitution saving throw or be restrained. The creature must repeat this saving throw every turn or else take an additional 40 bludgeoning damage.

Wave of Sand (Recharge 5-6). Melee Weapon Attack: +10 to hit, reach 60 ft., up to five targets. Hit: The creatures must succeed on a DC 20 strength saving throw or take 80 (10d12 + 20) bludgeoning damage, or half as much on a successful save.