Mine are:
Nicky - My name is Nick and my friend calls me this when I call her J.
Strawberry Shortcake - My gym teacher calls me this because I died my hair red.
Cherry - Several of my friends call me this because of my dyed hair.
Rihanna - My friend called me "Beyoncé" in science in front of my science teacher for a reason I don't even know, so my science teacher decided I'd be Rihanna because there's already another kid called Beyoncé...
Huevo - When I act like a ****ty Mexican hooker, people call me this.
Robbie - My real name is Robertson, and many say it's a "long" name, so most people call me it.
Robbie Cookie - My friend Olivia calls me this because she first said my middle name as "Cookie", despite it not being pronounced "Cookie".
And then there's the usual...
"******".
My nickname is Jules (full name: Julian). Nobody called me Jules growing up but I had this co-worker 4 years ago (who was straight but I was kind of in love with...) who was a good friend and started calling me it. It caught on after a while so a lot of my friends call me Jules now.
Jungle - My name is James which a nickname for James is 'Jim'/'Jimmy' and there was a some guy in a cartoon called "Jungle Jim" and my Grade 3 teacher called me Jungle. I've loved the name ever since.