I'm not the devver, but you can enter your name here if you've bought the name-in-game pack: http://rimworldgame.com/creative/index.php
You can't enter your appearance, I'm afraid, and I don't think the dev will make an exception just for you. If you have the Mercenary tier or above you can customize your skills though. See the Creative Rewards guidelines: https://docs.google.com/document/u/1/d/1HmLwOYk8e_kyQ4nEEfHtLr-vvPb03vkaOntnrVlPKM0/pub
You can't enter your appearance, I'm afraid, and I don't think the dev will make an exception just for you. If you have the Mercenary tier or above you can customize your skills though. See the Creative Rewards guidelines: https://docs.google.com/document/u/1/d/1HmLwOYk8e_kyQ4nEEfHtLr-vvPb03vkaOntnrVlPKM0/pub