I was in the end doing a few experiments on creative mode, i guess i looked at an enderman, because I started to hear the screeching they make, but it was a tad more terrifying, as it sounded rather vibratey, and echoey! I tested this in the overworld and the same thing happened. This does not happen in survival.

So to sum it up, i expected an enderman screech, and instead got a space demons dying screams... Quite terrifying at the time! The end already puts my nerves on... END!

Pun int-END-ed.