Who is nessy in Pinocchio?

In the context of "Pinocchio," there isn't a character named Nessy. You might be referring to "Nessus," a centaur from Greek mythology, or possibly confusing the character with someone else. In the classic tale by Carlo Collodi, key characters include Pinocchio, Geppetto, and Jiminy Cricket, but Nessy does not appear in the story. If you meant a different adaptation or character, please provide more details.