One has to admire Grendel's tenacity. For being such a minor player and number 88 on our list, his ego is bigger than most. Case in point: Hunter Rose came to Gotham City to looking for crime, but mostly wanting to challenge Batman to a match of wits - just to see if he could.
A corrupt youth named Eddie turned assassin Hunter Rose, Grendel operates best when pushing the limits of what he can and cannot do. Which makes his challenge to Batman even more fitting, given how arguably similar they are.
Hunter is a man of culture and learning, much like Bruce Wayne, who doesn't hesitate to strike down those who oppose him - much like Batman. But unlike Batman, Grendel is a debonair monster, a murderer who wears a mask because it's easier to exact justice when no one can see who their executioner really is. That power, the choice to use it in such away, combined with his electric fork (think a utility belt in the form of a twin-bladed spear) make Grendel a welcome addition to the list. If only he would get more play opposite Batman, and in the mainstream in general.