This rod strikes as a +1 heavy mace. Once per day, upon command (a free action), the head of the rod becomes that of an actual serpent for 10 minutes. During this period, any successful strike with the rod deals normal damage and poisons the creature hit. The poison deals 1d10 points of temporary Constitution damage immediately (Fortitude negates DC 14) and another 1d10 points of temporary Constitution damage 1 minute later (Fortitude negates DC 14). The rod only functions if the possessor is evil.