DCU IH Killer Croc
All Infinite Hero figures are highly detailed, but Killer Croc is arguably one of the best figures from the Batman universe. He is also one of the most expensive ones as he was available only in a six pack featuring Catwoman, Batman, Gordon and two cops, I believe.
Like most Batman villains, there are several versions of the Rogues' Gallery, but Killer Croc's has the best explanation. Every figure is different, and this figure is based on the Hush years (anyone remember when he fell in love with his doctor and she offered herself as a sacrifice? sheesh...). The figure is highly articulated and expressive even though his teeth are most often badly painted and stuck in that very neutral mold...
Croc is worth two scrawny Infinite Hero figures alone! While he isn't tall, he is big!
See what I mean? This figure can't be found under $20. I got it for around $40 about five years ago. I should have waited. It's a nice figure, but only good if you're an Infinite Hero collector, or if you're a Batman collector. I personally really like the aesthetic of this entire line. One Batman or one figure by itself seems pretty...eh. This is a very nice comics based line, and that's been one of my favorite things from Mattel in that whole 2004-2008 era.