Mysterious new power-player in Gotham City. His ulterior motive remains a mystery as does his past, but with his arrival came a new wave of former crooks turned metahuman powerhouses such as Precious Precious, Gee Gee Heung, and Qi Tsu. He provides his "seeds" to a select few, acting as implants that once rooted inside the body will grant their hosts extraordinary superpowers at the cost of their lives.

Mr. Bloom is created by Scott Snyder and Greg Capullo and is described as representing the weeds and cracks that keep sprouting in society between different groups based on dissatisfaction with the status quo. Anyone with the right motivation could become Mr. Bloom. It is known that 5 years ago, right after Zero Year, Bloom sold Man-Bat based implants to Peter Duggio that resulted in his death.