I had to go digging to find the version of the poster that inspired me for that group shot... sure enough, it's cropped so there's no Robin.
While I was backtracking through my old thread on Rebelscum, I also found these behind the scenes pics from taking this photo. Here's how it looked from above, revealing that I even had a fish in Lew's hand, unseen in the final photo:
Here's a shot from the side, revealing several blocks of styrofoam cut to put figures at the proper height:
Notice Kermit's head faces forward but his body faces backwards, to give him a more upward eyeline.
And here's a detail from an earlier version of the photo which I had to scrap because it looked like Bunsen was doing something gross:
Amazing what a difference is made by just a slight rotation of the wrist and elbow.
Alex