Long time ago I needed a nick and due to not wanting to rip it from somewhere, I began constructing one instead.
First of I wanted it to be a little special, so I picked the letter Z as a start as it's rarely used in danish. Next of a needed a vowel and the first one was "a", so I just took it.
Next up the third letter, where I for some random reason picked "c" as it's also the third letter in my real name. After the c it sounded logical with a k, as "ck" is quite common in english.
The last "er" was mainly just some sort of typical ending of a word describing something or someone.
Haven't heard of many others who got their nicks this way:D