Timothy "Tim" Murphy (b. 1978 (novel canon) b. 1983 (film canon)) is the grandson of John Hammond who was invited to Jurassic Park because his parents were going through a divorce. In the film, some of his characteristics were swapped from the novel, with those of his sister Lex Murphy. Being John Hammond's grandson, he is second-generation Scottish-American.
Tim will return in Jurassic World 3.