Hi, Pikachu. I removed the note about not being able to tell what dragon you get until you see the egg. The problem with that note is, depending on what combo you use, you can also get other 10 hour dragons. If Century and Glacier were the ONLY possible outcomes, the note might make sense, but since there could be other outcomes, we don't list them all.
Yes. I have been trying to emphasize the idea of there not being "one combo" for a dragon where you only need to match elements. For examlple, I used, Reindeer + Mud and Ghost + Seaweed and they both have the possible outcome of a Century dragon.
Hey, guess what! You just made your very first contribution to DragonVale Wiki! How exciting!!
I see you visited the User:PikachuDragon page, not a bad place to start. If you're looking for friends, remember to keep all your requests and friend-finding to the Friends page. If you have any questions you can take a look at the Community Portal or join us in chat, we're always happy to lend a helping hand in any way that we can.
Please leave me a message if you need any more help or just wanna say "Hey!".