Have you seen the new Lego series 19 Custom Minifigures? This is the Jungle Explorer minifigure, could this be a LEGO minifigure of Johnny Thunder? Comes with a chameleon and a magnifying glass, new hat and backpack. I see this minifigure being the part of may expeditions, and the little green critter is a keeper for sure.
The Explorer Minifigure from the LEGO CMF Series 19 appears in these sets:
71025 The LEGO Series 19 CMF (Complete Series of 16 Complete Minifigure Sets) (Release date 2019)