Well, the cat is out of the hat now
Thanks to Itaria, now we know that Series 18 will be a themed series, like Series 14 (the monsters series)
Series 18 will be released on April 1 2018
I want to say something
Almost 10 months ago, @VaderFan2187, a now banned member, gave us like half of the list for this series
Now we know the info he gave us was correct
So, VaderFan2187, if you are reading this: Thank you