Ah, what to say, what to say. Well, I have only one, a silver haired male kit whose name is Hal. He's actually on my icon. And if you're on the discord, you may have seen him before.
He looks very androgynous and is very short. His gills are more apparent than on most half-kits, though still just as useless. His gills flutter a bit when he's flustered, and that happens often. He also has a bad habit of constantly playing with his hands or holding them against his chest, or really, keeping them occupied in any way. It's mostly a mechanism to cope with stress or embarassment.
He's very gentle, pure and emotional, advocating peace whenever he can, and extremely opposed to violence, even if he would defend himself or his loved ones if needed. Also, he needs to be needed, so he really tries to help at any possible opportunity.
That aside, he really wants to be friends with everyone, and is a serial hugger, despite his usual nervousness and shy demeanor.
Overall, I really went for that "sheltered jewel" feel - a beautiful and innocent prince who never faced the horrors of the world and who tries to make friends with everyone, desperate for love and affection. He has a hard time dealing with being betrayed or with the idea people may stop liking him, which also means he's extremely forgiving even if someone wronged him.