Does breeding two of the same dragon always yield an egg of that same type?

In Dragonvale I noticed breeding two Pang Long dragons yields another Pan Long dragon, and advice for breeding Holiday dragons on the Dragonvale wiki suggests you can only get expired time-limited dragons by breeding two of the same dragon.

Does breeding two of the same dragon always give another one of the same dragon, or can they mix and create a hybrid dragon like other dragons?

Solution 1:

Generally they will breed a child of the same exact type, at least 95% of the time in my experience. However they can breed a hybrid of their elements.

When breeding two Chrome dragons (air/metal) repeatedly I found that once I got a Rust dragon (Metal+water)! This is because, apparently, on rare occasion an Air dragon breeds as a fire or water dragon instead of an air dragon.