I don't know much of Beast Boy's history, but you could do what I did with Raven. I took her up to when she would have joined, then spliced in history from after the Titans, and modernizing it a bit to dump her in the game. Because, yeah, with no Teen Titans there wasn't much to work with for her.<br/><br/>Raven didn't have much before them either, hence her bio being so short.