Tomwise is an elven poison maker, and an acquaintence of Hawke.
Tomwise met Hawke during Hawke's first year in Kirkwall. When approached by Hawke at any act, he will reveal that he used to make poisons for Athenril when Hawke was still smuggling.
He serves as a poison maker, selling poisons in Darktown. He will give you an initial poison recipe, like Lady Elegant gives you the recipe for an Elfroot Potion.