This is Lizario Modelle, a fashionistic Oxyphian who helps Kao in his battle against the Intruders. He looks like quite a fashion model who loves lights cameras and action, but deep down he's a very modest and polite type who just loves to help and make the world a better place. He's quite reclusive when not on stage, but always has a bright and confident smile on his face. He also tends to prefer to be called "Lizzie" or "Liz" due to his feminine nature (though his voice is still deep and whispery, he kind of sounds like the latest Shadow the Hedgehog.)
2. Despite his nature, he isn't particularly "gay" per se. Like most male stars, he is just really into feminine looking fashion and such, especially given he lives in a city. He is notably more feminine than most Starmaninjian males though, but is really just more Metrosexual.
3. He does have larger than usual breasts. They grew out as he grew up, but mostly by his will to be more attractive in a feminine way. They won't grow as large as Silver's or any female's, but will probably end up at least D cup size by the time he becomes an adult. These are more for appearance rather than utility though.
4. It's official. Amphian tails will have an elemental symbol on them when a particular Amphian shows mastery over an element. It's just Amphians though as they're the only species that seems designed for a very particular element natively, water. (Talzas do as well but they may get a similar treatment).
5. As stated, his voice and accent is meant to be similar to Shadow the Hedgehog from games like Sonic Free Riders. He tends to speak slowly and with emphasis, but doesn't say much because his parents are generally pretty mute themselves.
6. He's planned to be playable in Kao's second adventure, so you'll be seeing him quite a bit. His son is also playable in Stardra's second adventure as this guy helps introduce Ocealand in the story.