Nicklas is slang for extreme awesomeness. Nicklas is also the name of people being awesome.
In northern Europe Nicklas is used as a way of describing males with very large penises.
Random guy #1: "I can't believe that touch down"
Random guy #2: "That is so Nicklas"
Guy in showe: "OMFG!! You are hung like a horse! You must be a Nicklas"