Add More Mobs!!!!

Hey I'm just gonna enter this blog in the mineideas contest.
what you should add:
You should add more mobs to minecraft. Like sharks and whales. Sharks would be hostile. You could get food from whales and ride them. And more mobs to spawn at night like giants or minators.
Why you should add this:
You should add this to get minecraft a little more exciting. (minecraft is already exciting and fun.) Minecraft would be a bit more realistic with sharks and whales. I'm not saying you have to add the mobs from above. you could add horses, lam, etc.
I hope you enjoy this idea. Thanks for reading it! :D