I get the mini sized ones - just right for a hamster I think - not quite as big as them but big enough to be funny when they drag it in their house
I've had the alligators and toothbrushes (the antos ones from viovet).
Charlie went crazy for all of them but wouldn't touch the white/beige ones - I thought those were the algae ones. He slightly preferred the toothbrushes, which got chewed more.