Cobalt

I don't have a set in stone backstory for this guy yet, but here's a generalization

Cobalt is a blue betta, a transgender male that's fully transitioned, and asexual. He was born as a normal fish, but soon started to grow legs and walk on land. He'd gotten real tired of attracting people on the beach thinking he was some type of mermaid, when in reality he was just an anthropomorphic fish trying to get by in life. He very soon realized he was trans, and mostly stopped visiting his nearby beach since then.

He loves to wear tank-tops and beanies of any type, but he does like the color teal a lot, so he usually goes for those. He tries to be outgoing, but fucks up a lot, although he usually just brushes it off and tries to make a joke out of it.