Flat Quack is very cute, and the dogs like it. It is already missing a foot though. That's expected with 4 big dogs.
Wacky worm is perfect except we think that you should ditch the eyes. Our 11 month old border collie/grey hound ate the eyes off in less than a minute. I gave the worm to her, turned around to put packaging in recycling and the eyes were gone. It is a great tug/spin the dog toy.