The Dogfish is first mentioned in chapter XXIV, when Pinocchio, searching for his creator Mister Geppetto, is informed by a dolphin that he has likely been swallowed by the creature which "..for some days has come to wreak extermination and desolation in our waters".
The Dogfish makes its first appearance in chapter XXXIV when Pinocchio, recently transformed from a donkey to his puppet form, has entered the sea to escape from his former handler.