The species are incompatible and cannot interbreed.
Nothing A mount you can't fall off of.
Impossible.
A giraffephant.
An owlphant.
A zebraphant.
A walrusphant.
A koalaphant.
An ibexphant.
An octophantopus.
A raccoonphant.
A rhinodillophant.
A hedgedeerphant.