Gomes make many different kinds of poison.  In one of those they coat the tips of their ancient metal spears with a black sticky liquid.  When a human is stuck with the spear some flakes of metal and the sticky black poison are caught in the wound.  The poison makes the victims sleepy and easy to capture.  If the victims do get away they will find that their wound throbs more and more painfully if they come close to gomes in the future.  

 

Other poisons include potions and powders that can choke or blind a victim.  We have also seen that certain gomes, like Desperandum can hurl burning acid spitballs towards an enemy.  Bluebeard has concentrated collections of poisonous and flammable gas inside him that he can use to choke, poison, or burn his enemies.