Jeff was orignally part of a group of experimented on Sharks, given leggs and the ability to breathe air and walk on land.
Jeff the Baby Land Shark was created by Kelly Thompson and Daniele Di Nucuolo and first appeared in West Coast Avengers Vol.3 issue 7 (2019). His species already appeared in West Coast Avengers Vol.2 issue 1.
Major Story Arcs
Jeff was living in a secret lair of the supervillain who created the Land-Sharks. During an assault by the West Coast Avengers on the compount, Gwenpool found the baby land shark and immidiately took a liking to him. She named him Jeff the Baby Land Shark and introduced him to her other teammates from the West Coast Avengers. At first, the other heroes where sceptical of Jeff, but they soon embraced him. Jeff became friends with Clin Barton (Hawkeye)'s dog, Lucky the Pizza Dog.