Speed burst: By lowering their body to the ground and propelling themselves with their arms, Naga can move more quickly for a time. As a bonus action on their turn, if they have both hands free, they can increase their walking speed by 5 feet until the end of their turn.
Natural weapon: Naga's constricting serpentine body is a natural weapons, which they can use to make unarmed strikes. If they hit with their constrict attack, they deal bludgeoning damage equal to 1d6 + Strength modifier, and the target is grappled (escape DC 8 + proficiency bonus + Strength modifier). Until this grapple ends, the target is restrained, and they can’t constrict another target.
Poison immunity: Naga are immune to poison damage and can’t be poisoned.
Poison affinity: Naga gain proficiency with the poisoner’s kit.
Crushing coils: When a creature is restrained by a Boakin's Constrict, it takes 1d6 bludgeoning damage at the start of each of its turns.
Enduring scales: Boakin have advantage on saving throws against being knocked prone or moved against their will.
Swamp stalker: Anacondas move unseen through water and murk, striking from the depths. They gain a swim speed equal to their walking speed. They have advantage on Stealth checks made in wetlands, swamps, or while submerged. If they attack a creature while hidden and in water, the attack deals an additional 1d8 poison damage.