Background Pony #75F9
A bit late now, but I would have labeled them as Equus Titanis Sapiens. With Titanis denoting the enormous size, obviously, and Sapiens specifically denoting that they are in fact intelligent beings. We ourselves are Homo Sapiens Sapiens after all.
Although, if modern archeology is anything to go by, Celestia may just get a separate designation regardless unless the ponies specifically state that they’re actually the same species. XD
But overall wonderful work.