• Amphibious: Kalka-Kylla can breathe air and water.
• False Appearance: While Kalka-Kylla remains motionless and hidden in its shell, it is indistinguishable from a polished boulder.
• Shell: Kalka-Kylla can use a bonus action to retract into or emerge from its shell. While retracted, Kalka-Kylla gains a +4 bonus to AC, and it has a speed of 0 and can't benefit from bonuses to speed.
• Multiattack: Kalka-Kylla makes two claw attacks.
• Claw: Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) bludgeoning damage, and if the target is a Medium or smaller creature, it is grappled (escape DC 13). Until this grapple ends, the target is restrained. Kalka-Kylla has two claws, each of which can grapple only one target.