No, you cannot. The GFP gene has been taken from jellyfish DNA and inserted in the axolotl DNA. It is a genetically modified organism. Unless you are planning some backyard genetic engineering, it's not possible. You would need some pretty sophisticated laboratory equipment, and access to the proper jellyfish DNA. All captive GFP Axolotl's are direct descendants of animals that have had their DNA manipulated in a lab setting. If you want a GFP animal, I would suggest buying one. Please check the laws in your country, as I know they are illegal in some European countries. I personally don't think the GFP trait is cruel, it is a mutation we have selectively bred for, like albinoism and melanoid animals. The only difference is that this trait was artificially introduced by human intervention. I do think that exposing the animals to UV light to express the trait can be harmful and should be discouraged. UV light is proven to be harmful to DNA, so a mutation that encourages large quantities of UV exposure could be unfortunate for the animal in the wrong hands.