The fish thing? I've heard that too, I don't know what it means but when one of my teens gets out of bed I shall ask.
Actually, I've just asked 'Urban Dictionary' -
(a) derogatory term for a homosexual male. So I would assume it's an evolution of the 'gay' moniker.
(b)term for biological women used primarily by gay men, either in a positive or derogatory way.
(c) a mexican?
(d) a poker player who loses.
I will double check with tho' what it is likely to be in common teen-speak.
The child though who never gets bullied is often short in stature compared to peers, quirky, glasses .... ah but he/she is the comedian - popularity often goes with humour. Class Clowns don't get bullied because they create diversions. They have learned that humour is a situation difuser but more importantly, because they don't have the physical ability to compete it is much easier to turn everyone into their friend. That is a life skill.
The ability to make (lots of) friends is a gift that not everyone possesses. In an ideal world we would all be equally gifted but in reality we are not. Some people are unpopular, through no fault of their own.
Conversely, some people actively court unpopularity because negative attention is attention and any attention is good attention. My son had one of those in his primary class. We were discussing him one day and my son came out with quite an observation "Some people have victim stamped on their head - and he's one of them - he revels in it and enjoys being one of lifes victims". I've had the opportunity to watch that boy where I work and my son was spot on with his assessment when they were both 10.
I've also seen girls who could allow them selves to be bullied (pretty, slim , clever) if they had different character traits. One example, an uber-bitch thought she would have a go at Miss-Pretty-Perfect - who flashed a smile and bounced the insult back as a compliment - again it's very difficult to keep being nasty if someone is saccarine to your face and infront of your peers.
So there are tactics in not facilitating bullies - that you will meet in every walk of life - and most bullying will be verbal not physical. Bullying by its nature is designed to undermine confidence and gind someone down. So with the best will in the world, no amount of self defence classes will stop someone telling you are fat/spotty/smelly/spekky-4-eyes etc etc