The question is simple: Can a character choose to take a mount from his list and also be equipped with the Horned One?
Expounding: A Horned One is considered an enchanted item that can be destroyed via spells that target enchanted items courtesy of the official FAQ. Moreover, it's never referred to as a mount so a model with it on a cold one model would simply be modeled WYSIWYG with the enchanted item that functions AS IF it were a cold one.
Morever, there is precedent in that you can take a mundane weapon from a characters list but then also a magical weapon as well. It's not a perfect example of course as the uses for mounts and weapons are different but is a good example in that they share the same circumstances.
Also, for those that would insist that it is still a mount, no where in the BRB does it mention not being able to take more than one mount. This limitation on mounts, much like hand weapons, is only imposed in the army list where it says "One Choice Only" in which case the Horned One is not on that list, thus not constrained by that limitation.
My Opinion: You could take a Carnosaur and the Horned One much like a mundane hand weapon and a magical hand weapon. Magical weapons contain rules that state that you must select the magical weapon over any mundane weapons but mounts do not have any such rules (aside from the idea that it's not a mount anyway). So you mount your model with it's enchanted item on the Carnosaur and the Horned One would be 'hidden' or 'stuffed away' as would a mundane hand weapon when a magical one is used in it's place. Then once the Carnosaur is slain, the Cold One model is used to represent the Horned One not as a mount but as an appropraite representation of the enchanted item.
What does everyone else think?
Expounding: A Horned One is considered an enchanted item that can be destroyed via spells that target enchanted items courtesy of the official FAQ. Moreover, it's never referred to as a mount so a model with it on a cold one model would simply be modeled WYSIWYG with the enchanted item that functions AS IF it were a cold one.
Morever, there is precedent in that you can take a mundane weapon from a characters list but then also a magical weapon as well. It's not a perfect example of course as the uses for mounts and weapons are different but is a good example in that they share the same circumstances.
Also, for those that would insist that it is still a mount, no where in the BRB does it mention not being able to take more than one mount. This limitation on mounts, much like hand weapons, is only imposed in the army list where it says "One Choice Only" in which case the Horned One is not on that list, thus not constrained by that limitation.
My Opinion: You could take a Carnosaur and the Horned One much like a mundane hand weapon and a magical hand weapon. Magical weapons contain rules that state that you must select the magical weapon over any mundane weapons but mounts do not have any such rules (aside from the idea that it's not a mount anyway). So you mount your model with it's enchanted item on the Carnosaur and the Horned One would be 'hidden' or 'stuffed away' as would a mundane hand weapon when a magical one is used in it's place. Then once the Carnosaur is slain, the Cold One model is used to represent the Horned One not as a mount but as an appropraite representation of the enchanted item.
What does everyone else think?