Student circles (Ger/UK)

I need you, students from Europe!

So basically next year I will travel a lot in Germany and Great Britain to visit my friends who will stay there as Erasmus students. They will mostly stay in London, Berlin and Heidelberg. I would kike to know if there are such kind of student circles in those cities.
I'm pretty sure it does so if you've ever heard about them, it would be nice of you to submit some informations.

But the question is: what are students circles? It's a non-official group of students who spend their evenings together to drink, meet each other and of course for sexual relations lolwut.
To enter most of these circles you need to be baptized (the famous student hazing (there is no proper translation actually, this word means bizutage which is the French version and definitely sucks).
Students most of time wear some special clothes with the name of their circle and their nickname on it. They also have a headgear (a penne, a calotte or even a faluche In France (some french students are still baptized even though the hazing is prohibited (for the French speakers, this article is hilarious))) and sing a lot of songs with harsh words. Kinda simple to identify them.

I already know it does exist in Finland as a friend of mine met some baptized students and took this picture in Helsinki so it wouldn't be too complicated to find them.

It'd kind of you to help me, I really want to meet all facets of the students there!