Phantom Serpents are very dangerous mobs that possess many abilities. They spawn only in Phantania, usually alone. They have 20 <3 and can be potentially life-threatening without the right tools.
Phantom Serpents will sneak up on the Player while invisible (they can be seen by the blurred distorted areas their aura creates when approaching) and hiss at them loudly to momentarily startle them and leave them unable to attack. The Phantom Serpent then coils around the Player and tries to choke them. The only way the Player can escape this attack is to attack their neck, which has a chance to make them let go. They are dazed for a few seconds, then try to coil around them again. Every half-second the Phantom Serpent stays coiled around the player, they deal half a <3. Sometimes, they also snatch up Player's items and eat them while they are immobilized. When killed, they drop nothing.
Phantom Serpents spawn only in Phantania.