Contrary to popular belief, this serpent did not normally strike in water; most victims were on dry land or a marsh island when they strayed into a snake run. These snakes only attacked when their "runs" were encountered, and then it bit with astounding quickness. A nathrach's critical strike was accompanied by a muscle poison that caused bleeding, bruises, and swelling . The venom was not very toxic but did cause bleeding, bruises, and swelling. It was designed to stun small rodents before the snake enveloped and crushed them.
The arnathrach, or royal nathrach, was a much larger cousin that inhabited the brackish waters near the coasts.
- Retrieved from [Realms of Arda]; original reference: [ICE MERP 2012]