The Mule is a very special mix – it has a donkey father and horse mother, and they often inherit the best qualities of both. "The mule is an example of hybrid vigor, Charles Darwin wrote: The mule always appears to me a most surprising animal. That a hybrid should possess more reason, memory, obstinacy, social affection, powers of muscular endurance, and length of life, than either of its parents, seems to indicate that art has here outdone nature." They are typically very strong for their size compared to horses and are able to cope with bad weather better than donkeys. Mules rarely become ill and their behavior is Intelligent and sensitive. In the right home, they can make great companions for other equines, and wonderful pets. However, if they are unhandled or not correctly trained, mules have the potential to be dangerous. The inner shapes of Mule Cargo are almost identical between the Regular and the Heavy weight. This shared genom make them very powerful pair and a useful design tool for display purposes.