Need Ideas for names for a dragon turtle!

I need some ideas for a giant dragon turtle with a castle on his back for my game. I want something epic that sounds ancient and mysterious (not scary) but can also has a natural nickname that sounds kind of cute. Male or female names are welcome. I also want it to avoid being a real name or a name of another character. The nickname could be more know if appropriate. Some names inspiration from famous characters are Gandalf, Gilgamesh, Gortash and for nick-names Grog. Doesn't have to start with a G but you get bonus points if it does. Thanks!