If you have a bumblebee you can breed it to a pastel to get killer bee's. It will be a small percent chance since you can also get: Bee's, Spiders, Pastels, and Normals.
Don't know what kind of budget you have or even if you are in the market for a new snake, but I recommend getting a lemon blast. Its a Pastel Pinstripe. You'll get some amazing combos out of it. I have 2 Bee's and that will be the next project I look forward to.