The Hurley saved us! I never write reviews, but wanted to review this because I want anyone who has an aggressive chewer and who was skeptical about these toys like I was to BUY THIS NOW! We have a golden retriever (now almost 2 yrs) who is a VERY aggressive chewer. He loves to carry toys in his mouth, but if he figures out that he can chew it up, that's it! He can chew up kongs (yes, even the black ones) and anything else out there labeled as "tough" or "indestructible". These zogoflex toys are AWESOME, and the ONLY thing that he has not been able to chew up within 5 minutes. I think the Hurley is the toughest, and I would recommend trying that first if you have a very aggressive chewer. Our dog loves the Tux the most, probably because eventually he has been able to chew off very small pieces (but that's after almost a year of serious chewing!), the huck is also great for outdoor play. We did not have luck with the zisc or bumi, those were chewed within minutes. I love this toy! We have 3 of them!