We have all heard of the usual. Herobrine, Entity 303, they can't compare one bit to the monster I will tell you about. The the playername "ILOVESHOVELS", or "SHOVELSHOVELS" is very dangerous, and if you ever see that person, or thing, join your MCPE game or server, leave immediately. Maybe you will get out before they target you. What this user can do, I have seen first hand.
I was at my friend's house while he was playing an MCPE small survival server. When the user "ILOVESHOVELS" Joined, he didn't care too much. He explained to me that everyone on the server knew each other and all had god armor, so when some new players joined they would go to to spawn and kill them. He typed in /spawn and others were already there, overloading the chat with disbelief.