What works against salads: Merlin's Shield (level 5 Stone Magic, you can buy scrolls in the Mages Guild) plus high resistance to poison (the Snakeskin trait, Lizzards are born with it, one of your guys can get the trait in the Snake Temple). Merlin's Shield itself isn't enough - you get poisoned though but you won't die so quickly.
Note that the Algamesh Amulet is an equivalent of the Snakeskin trait. You are supposed to give it to Kerielle and get a potion from her but - you can give it to Kerielle and then buy it back from her
You will have both the potion and the amulet.