Iggy is a young Iguanodon that Eric Kirby had befriended in the book "Jurassic Park Adventures: Survivor". It was encountered during Eric's eight week stay on Isla Sorna when it scared off a Velociraptor that was about to kill Eric. Eric then repaid the favor as he sacrificed his hope of communicating with the outside world to save Iggy's life from a pack of vicious raptors.
His name is a nod to the novels where Lex Murphy named a baby trike "Ralph". Ralph, Iggy, Clarence, and the three raptors from the comic books are the only other dinosaurs to have a name given to them by a character.