Nick Koopa is the oldest koopaling ans the most powerful. He looks like Ludwig nut he has yellow shell and yellow-fuchsia glasses. He has the special ability to have all koopalings powers. He is the strongest koopaling.
When he was young,(beta sprites)he used to have yellow glasses.
The power has given from Morton Koopa Sr. and Bowser, that's why he is the most powerful koopaling. In battles he is very difficult. So, the best way to kill him is an Invicibility Leaf.