Dr. Julian Martin is a marine biologist who lives in the Great Barrier Reef. '
Sabrina Spellman admired Dr. Martin for his work as an activist and researcher of sea life. However, Sabrina saw another side of Dr. Martin when he revealed that he planned on capturing and exposing the mermaid colony who secretly live in the reef, in his claim for fame. This proved life threatening as Dr. Martin was the only one with the antidote to the infection that was affecting the merpeople. Sabrina was able to get Dr. Martin to see the error of his ways and he decided against his plan.