From the Super Mario Wiki
Helvetica is a struggling author named after the Helvetica font. He is encountered in Super Paper Mario, living on the first floor of Flipside. He writes slowly, so his works are never published, unlike his Flopside counterpart, the best-selling author, Garamond. Helvetica actually sends Garamond ideas in his dreams, and the two eventually switch places. Helvetica sometimes thinks he would be better off working as a cook, seeing as his culinary works make even chefs jealous.