He started his career as a press artist and part-time cartoonist on The Mercury, drawing under the name "Jeff". He moved to Melbourne and started at The Sun News-Pictorial in 1964. Hook became the full-time cartoonist for The Sun News-Pictorial (later to be merged with the afternoon newspaper The Herald to become the Herald Sun). Jeff was famous for hiding a fishhook in his cartoons, which became his "trademark", and looking for the hidden fishhook became a widespread morning pastime amongst readers of The Sun News-Pictorial.
Hook first gained international recognition in 1967 for his cartoon about the end of the Six-Day War, "The three wiser men", which was re-published widely outside Australia, including in The London Times.[4]
Hook retired from the Herald Sun in early 1993, but continued to freelance, doing a regular editorial cartoon for the Sunday Herald Sun while devoting his time primarily to painting. That continued until the year 2000, when he largely stopped cartooning after holding his first exhibition at the Australian Guild of Realist Artists (AGRA) gallery and pursued his love of painting full-time. After that, Hook exhibited widely at regional art shows and galleries in Australia and held a second exhibition at the AGRA Gallery in 2005.
Over the course of his career, Hook did numerous cartoons and illustrations for papers, magazines and 46 books, including two children's books Harry the Honkerzoid and Planet of the Honkerzoids, written by one of his sons, Brendan, and a children's book of his own, Jamie the Jumbo Jet, which was first published in the mid-1970s, and was revised and reprinted in 1998.
After retiring from full-time cartooning, Hook was awarded the Australian Black and White Artists Club's Silver Stanley Award for lifetime achievement in 1998;[5] and, on 20 March 2009, he was awarded a lifetime achievement award by the Melbourne Press Club.[8] In January 2012, he was awarded an Order of Australia Medal for "services to the print media as a political and social commentator, and as a cartoonist".[9][10]