All Kong toys are durable, but none are invincible. There is, however, a special variety made to withstand tougher chewing. Introducing: the KONG Extreme. This toy represents the most durable strength in the range. Designed for the toughest of chewers, this toy is ultra-durable and made with a natural rubber formula. So, be sure to check out other Kong toys if your pooch gets through their current ones too quickly.