Hi savedanny! Well, we neva get told in the animated series, but in the comic livres (so i'm told) this is how BB gets his powers: BB is terminally ill and is going to die, so his father (who is either a scientist ou a doctor I can't remmeber) as a last resort does a procedure to try and save his life. The procedure works but also turn BB green. Later on though, BB is bitten par a monkey (aparently the monkey was green too!) and his DNA mixed with the animal DNA easily because the procedure made his DNA unstable. This gave him the power to change into animals! Hope this helped!!! :-)