The Titans were supposed to be a race of giant "Gods" that ruled the earth until they were overthrown by the Olympian "Gods" or the greek gods of mythology. The Titans were the offspring of Gaia (Mother Earth and Uranus) if I remember correctly. I may be wrong on this so correct me if I'm wrong. I don't know if the centaurs and other so-called mythological creatures were created by the Atlanteans although there has been plenty of speculation as to whether or not they ever really existed and if so, whether they were created by DNA manipulation by technologically advanced extraterrestrial entities. Yes, the Bible does make reference to the Nephilim which were supposed to be the giant offspring of human females and fallen angels. The Bible also makes reference to a creature in the waters that was called a Leviathan which some speculate may have been some sort of dinosaur. This is all very interesting of course but unfortunately no one knows for sure.