Spider Climb. The gem stalker can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Unusual Nature. The gem stalker doesn't require food or drink.

Multiattack. The gem stalker makes four Claw attacks.

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:10 (2d6 + 3) slashing damage.

Crystal Dart. Ranged Spell Attack: +5 to hit, range 30 ft., one target. Hit:7 (1d10 + 2) force damage, and one of the following effects occurs, determined by the kind of dragon that created the gem stalker:

Amethyst. The gem stalker can teleport to an unoccupied space it can see within 30 feet of it.

Crystal. The gem stalker gains a number of temporary hit points equal to the damage dealt.

Emerald. The target must roll a d4 and subtract the number rolled from the next attack roll it makes before the start of the gem stalker's next turn.

Protective Link. When another creature the gem stalker can see within 30 feet of it is about to take damage, the gem stalker reduces that damage by 10 (3d6). The gem stalker then takes damage equal to that amount.