Dream About Harry Potter Trailer And Monster Attack

I was watching a Harry Potter trailer on a TV screen and saw scenes I have never seen before but characters I do know such as Harry Potter, and the Voice of Hermione Granger yelling "HELP!" but there was one person in one of the scenes I had never seen before but I saw this new character at the end of the trailer as the trailer played on to the end my mind was panicking desperately trying to type something else in the YouTube search bar on my phone when the trailer ended I was then greeted with grunt then a massive thud immediately after I immediately woke up not wanting to find out what it was and I'm kinda glad I did because what I saw next was a massive troll standing over me like a skyscraper and the next thing I know BAM! the monster hits the me in dream square in the face followed immediately after by the loudest and the most bone-chilling roar I have ever heard that was the end of it.