I used Carrie's idea of attaching the penguin to a container but used a plastic fish bowl (which my husband so graciously drilled into for the mouth) instead of a tissue box. I figured it went with the whole "fish" theme and it can take quite a beating from the kids.
I then added paper clips to each little fish card as the child produced the target.
Once our penguin had eaten all of the fish, we used a magnetic fishing pole to remove each one to elicit more productions!
The kids absolutely LOVED this activity!!