Running a 5th edition Oriental Adventure campaign based on some rules I converted a while back. Basically one big playtest. The players found an earth elemental gem which summons a Japanese equivalent of an earth elemental.  Here is the PC version.

Large elemental
Armor Class 17
Hit Points 126
Speed 30 ft., burrow 30 ft.
STR                 DEX    CON                INT     WIS                CHA
20 (+5)        8 (-1)  20 (+5)        5 (-3)  10 (+0)        5 (-3)
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities exhaustion, paralyzed, petrified, poisoned, unconscious
Senses darkvision60 ft., tremorsense60 ft., passive Perception 10
Languages Terran

Earth Glide. The elemental can burrow through nonmagical, unworked earth and stone. While doing so, the elemental doesn’t disturb the material it moves through.

Siege Monster. The elemental deals double damage to objects and structures.

Slam. Melee Weapon Attack:+7 to hit, reach 10 ft., one target.
Hit: 14 (2d8 + 5) bludgeoning damage and the target is grappled (Escape DC 15).